RESUMEN
BACKGROUND: Toxoplasma gondii infection causes intestinal inflammation and diarrhea indicating possible intestinal motor dysfunction. Anatomical studies have shown alterations in the colonic myenteric plexus, but it is unknown whether this impacts motility and therefore whether motility is a target for treatment. We determined whether colonic coordinated movements are compromised by toxoplasmic infection and how it is associated with anatomical changes. METHODS: Male Wistar rats were evaluated at 6, 12, 24, 48, and 72 hours and 30 days postinfection (dpi) and controls. Infected rats received orally 5 × 103 sporulated oocysts of strain ME-49 (genotype II) of T gondii. The colon was collected for anatomical analysis (including the myenteric plexus immunolabeled with HuC/D, nNOS, and ChAT) and motility analysis in vitro (conventional manometry). Fecal output was measured daily. KEY RESULTS: At 12 hours postinfection, T gondii caused hypertrophy of the muscularis externa layer of the distal colon. There was loss of total, nitrergic, and cholinergic myenteric neurons in the proximal colon at 30 day postinfection (dpi); however, only loss of cholinergic neurons was found in the distal colon. Contractile complexes in the middle and distal colon were longer in duration in infected animals, which was associated with slower migration of the colonic motor complex. However, gastrointestinal transit time and fecal pellet output remained unchanged during the T gondii infection. CONCLUSIONS AND INFERENCES: Toxoplasma gondii caused myenteric neuronal loss in the proximal and distal colon and altered the motility pattern in the middle and distal colon to a more propulsive phenotype.
Asunto(s)
Colon/inervación , Motilidad Gastrointestinal/fisiología , Músculo Liso/inervación , Neuronas/patología , Toxoplasmosis/fisiopatología , Animales , Colon/fisiopatología , Músculo Liso/fisiopatología , Plexo Mientérico , Complejo Mioeléctrico Migratorio/fisiología , Ratas , Toxoplasmosis/patologíaRESUMEN
BACKGROUND: This study was designed to evaluate whether overconsumption of NaCl, a well-known risk factor for hypertension, leads to erectile dysfunction in rodents. METHODS: Male Wistar rats received regular chow (control group) or 4% NaCl chow for 24 weeks and were subjected to blood pressure measurement and apomorphine-induced erection. Moreover, cavernosal strips from both the control and 4% NaCl groups were evaluated in organ baths. RESULTS: Animals subjected to 4% NaCl chow did not develop hypertension but presented a significant reduction in the total number of erections following apomorphine administration as compared with the control group. The addition of high KCl or phenylephrine resulted in similar contractile responses in the corpus cavernosal strips from both the control and 4% NaCl groups. However, electrical field stimulation-induced contraction was significantly enhanced in cavernosal strips from animals exposed to 4% NaCl. Incubation of Y-27632, but not of atropine and Nω-nitro-l-arginine methyl ester (L-NAME), entirely prevented the potentiation of the contractile responses evoked by electrical stimulation. The enhanced contractile responses evoked by electrical stimulation found in the high-salt group were also avoided in the absence of extracellular calcium. Concentration-response curves of CaCl2 revealed augmented contractility in response to extracellular calcium in cavernosal strips from the 4% NaCl-treated rats, compared with control samples. CONCLUSIONS: A high-salt diet alone rendered the animals less responsive to apomorphine-induced penile erection and enhanced neurally mediated contractile responses in the corpus cavernosum, a clear indication that overconsumption of sodium can lead to erectile dysfunction even without the development of hypertension.
Asunto(s)
Apomorfina/farmacología , Disfunción Eréctil/etiología , Contracción Muscular/efectos de los fármacos , Músculo Liso/inervación , Erección Peniana/efectos de los fármacos , Pene/inervación , Cloruro de Sodio Dietético/toxicidad , Animales , Señalización del Calcio , Estimulación Eléctrica , Disfunción Eréctil/metabolismo , Disfunción Eréctil/fisiopatología , Masculino , Ratas Wistar , Quinasas Asociadas a rho/metabolismoRESUMEN
We developed a novel murine model of long-term infection with Trypanosoma cruzi with the aim to elucidate the pathogenesis of megacolon and the associated adaptive and neuromuscular intestinal disorders. Our intent was to produce a chronic stage of the disease since the early treatment should avoid 100% mortality of untreated animals at acute phase. Treatment allowed animals to be kept infected and alive in order to develop the chronic phase of infection with low parasitism as in human disease. A group of Swiss mice was infected with the Y strain of T. cruzi. At the 11th day after infection, a sub-group was euthanized (acute-phase group) and another sub-group was treated with benznidazole and euthanized 15 months after infection (chronic-phase group). Whole colon samples were harvested and used for studying the histopathology of the intestinal smooth muscle and the plasticity of the enteric nerves. In the acute phase, all animals presented inflammatory lesions associated with intense and diffuse parasitism of the muscular and submucosa layers, which were enlarged when compared with the controls. The occurrence of intense degenerative inflammatory changes and increased reticular fibers suggests inflammatory-induced necrosis of muscle cells. In the chronic phase, parasitism was insignificant; however, the architecture of Aüerbach plexuses was focally affected in the inflamed areas, and a significant decrease in the number of neurons and in the density of intramuscular nerve bundles was detected. Other changes observed included increased thickness of the colon wall, diffuse muscle cell hypertrophy, and increased collagen deposition, indicating early fibrosis in the damaged areas. Mast cell count significantly increased in the muscular layers. We propose a model for studying the long-term (15 months) pathogenesis of Chagasic megacolon in mice that mimics the human disease, which persists for several years and has not been fully elucidated. We hypothesize that the long-term inflammatory process mediates neuronal damage and intramuscular and intramural denervation, leading to phenotypic changes in smooth muscle cells associated with fibrosis. These long-term structural changes may represent the basic mechanism for the formation of the Chagasic megacolon.
Asunto(s)
Enfermedad de Chagas/patología , Modelos Animales de Enfermedad , Sistema Nervioso Entérico/patología , Megacolon/patología , Neuronas/patología , Animales , Enfermedad de Chagas/complicaciones , Desnervación , Femenino , Megacolon/complicaciones , Ratones , Músculo Liso/inervaciónRESUMEN
AIM: To assess the effects of ME-49 Toxoplasma gondii (T. gondii) strain infection on the myenteric plexus and external muscle of the jejunum in rats. METHODS: Thirty rats were distributed into two groups: the control group (CG) (n = 15) received 1 mL of saline solution orally, and the infected group (IG) (n = 15) inoculated with 1 mL of saline solution containing 500 oocysts of M-49 T. gondii strain orally. After 36 d of infection, the rats were euthanized. Infection with T. gondii was confirmed by blood samples collected from all rats at the beginning and end of the experiment. The jejunum of five animals was removed and submitted to routine histological processing (paraffin) for analysis of external muscle thickness. The remaining jejunum from the others animals was used to analyze the general population and the NADH-diaphorase, VIPergic and nitrergic subpopulations of myenteric neurons; and the enteric glial cells (S100-IR). RESULTS: Serological analysis showed that animals from the IG were infected with the parasite. Hypertrophy affecting jejunal muscle thickness was observed in the IG rats (77.02 ± 42.71) in relation to the CG (51.40 ± 12.34), P < 0.05. In addition, 31.2% of the total number of myenteric neurons died (CG: 39839.3 ± 5362.3; IG: 26766.6 ± 2177.6; P < 0.05); hyperplasia of nitrergic myenteric neurons was observed (CG: 7959.0 ± 1290.4; IG: 10893.0 ± 1156.3; P < 0.05); general hypertrophy of the cell body in the remaining myenteric neurons was noted [CG: 232.5 (187.2-286.0); IG: 248.2 (204.4-293.0); P < 0.05]; hypertrophy of the smallest varicosities containing VIP neurotransmitter was seen (CG: 0.46 ± 0.10; IG: 0.80 ± 0.16; P < 0.05) and a reduction of 25.3% in enteric glia cells (CG: 12.64 ± 1.27; IG: 10.09 ± 2.10; P < 0.05) was observed in the infected rats. CONCLUSION: It was concluded that infection with oocysts of ME-49 T. gondii strain caused quantitative and plastic alterations in the myenteric plexus of the jejunum in rats.
Asunto(s)
Yeyuno/inervación , Músculo Liso/inervación , Plexo Mientérico/parasitología , Plasticidad Neuronal , Toxoplasma/patogenicidad , Toxoplasmosis/parasitología , Animales , Biomarcadores/metabolismo , Dihidrolipoamida Deshidrogenasa/metabolismo , Modelos Animales de Enfermedad , Masculino , Plexo Mientérico/metabolismo , Plexo Mientérico/fisiopatología , Neuroglía/metabolismo , Neuroglía/parasitología , Neuronas Nitrérgicas/metabolismo , Neuronas Nitrérgicas/parasitología , Ratas Wistar , Factores de Tiempo , Toxoplasmosis/fisiopatología , Péptido Intestinal Vasoactivo/metabolismoRESUMEN
Diabetes augments the risk of hypertension. Although several factors have been implicated in the development of such hypertensive state, we designed this study to investigate blood pressure development, the activity of angiotensin-converting enzyme (ACE) in blood as well as sympathetic neurotransmission in the vas deferens of diabetic rats. We used streptozotocin (STZ)-induced diabetic rats (60 mg/kg) in order to evaluate the systolic blood pressure (SBP), ACE activity and peripheral sympathetic neurotransmission. We observed the following changes of parameters: increase of SBP, decrease of heart rate, augmentation of plasma ACE activity, enhancement of phasic and tonic vas deferens contractions elicited by electrical stimulation at 5 Hz, increase of maximal response to noradrenaline (NA) and decrease of adenosine triphosphate (ATP)-elicited contraction of vasa deferentia. The results reveal that in the development of hypertension in diabetic rats, augmentation of circulating ACE activity precedes the sympathetic dysfunction. Additionally, it seems that the purinergic and noradrenergic neurotransmission is compromised.
Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Hipertensión/etiología , Músculo Liso/inervación , Peptidil-Dipeptidasa A/sangre , Sistema Nervioso Simpático/fisiopatología , Conducto Deferente/inervación , Animales , Presión Sanguínea , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/enzimología , Diabetes Mellitus Experimental/fisiopatología , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Frecuencia Cardíaca , Hipertensión/sangre , Hipertensión/enzimología , Hipertensión/fisiopatología , Masculino , Contracción Muscular , Fármacos Neuromusculares/farmacología , Ratas , Estreptozocina , Sistema Nervioso Simpático/efectos de los fármacos , Sistema Nervioso Simpático/metabolismo , Transmisión Sináptica , Sístole , Factores de Tiempo , Regulación hacia ArribaRESUMEN
Because of the few studies that emphasize the in vivo use of amphetamine and ethanol, and their consequences on autonomic neurotransmission, we decided to study the effect of these drugs on peripheral noradrenergic neurotransmission of young animals. We used contractions of the vas deferens of adolescent rats as a model for the study of pre-treatment with both agents. The 30 to 40 day old adolescent rats were pre-treated with amphetamine, at doses of 3mg/kg, or ethanol at doses of 1.2 g/kg. Both agents were also used simultaneously to investigate possible interactions. The group treated with amphetamine showed a potentiation of the vas deferens contractions evoked by noradrenaline and barium (about 20%), as well as time-response contractions of calcium (about 20%). However, the response to electrical field stimulation (EFS) was not significantly changed, but the content of noradrenaline was reduced by about 50%. The group treated with ethanol showed a decrease in vas deferens contractility to noradrenaline, phenylephrine, and barium, by less than 20%. In this group, contraction by EFS was reduced by about 40% (Tonic, 2 Hz) and 20% (Phasic, 5 Hz), but the response to calcium was not changed. As after amphetamine, the content of noradrenaline was reduced by about 50%. In the group treated with amphetamine+ethanol all the changes described after the single treatments with amphetamine or ethanol were neutralized. It is concluded that a functional antagonism was shown between amphetamine and ethanol when administered simultaneously on peripheral sympathetic neurotransmission in vas deferens of adolescent animals.
Asunto(s)
Neuronas Adrenérgicas/citología , Neuronas Adrenérgicas/efectos de los fármacos , Anfetamina/farmacología , Etanol/farmacología , Transmisión Sináptica/efectos de los fármacos , Conducto Deferente/citología , Neuronas Adrenérgicas/metabolismo , Animales , Calcio/metabolismo , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Masculino , Músculo Liso/inervación , Norepinefrina/metabolismo , Ratas , Ratas Wistar , Sistema Nervioso Simpático/efectos de los fármacos , Sistema Nervioso Simpático/fisiología , Factores de Tiempo , Conducto Deferente/efectos de los fármacos , Conducto Deferente/metabolismo , Conducto Deferente/fisiologíaRESUMEN
PURPOSE: To assess in vitro the correlation between the number of neurons and the sensitivity to cholinergic drugs and acetylcholinesterase activity in chagasic patients. METHODS: A 3 x 1 cm strip of the muscle layer of the anterior part of the stomach, always close to the angular incisure, was removed from 10 chronic chagasic patients (6 men) submitted to megaesophagus or megacolon surgery and from 10 non-chagasic patients (4 men) submitted to other types of surgery (control group), aged on average 52.3 and 50.1 years, respectively, for histological and pharmacological studies. The action of cholinergic drugs was investigated in isolated preparations according to the superfusion method of Ferreira and Costa, and acetylcholinesterase activity was determined by the method of Ellman. For neuron count, the strips were cut into 8 µm sections according to the method standardized by Alcântara. RESULTS: There was a difference in number of neurons between the chagasic (5,6) and control (7,3) groups. Acetylcholinesterase activity, in moles of hydrolyzed substrate per minute per gram tissue, was reduced in chagasic patients (4,32) compared to the controls (7,30). No hypersensitivity of the gastric musculature to cholinergic drugs was detected, with a reduced maximum response to carbachol and betanechol in the chagasic group. CONCLUSIONS: The reduction of neurons in the myenteric plexus of the stomach of chronic chagasic patients can be demonstrated even in the absence of clinical chagasic gastropathy. The hypersensitivity of the gastric musculature to cholinergic drugs probably depends on intense denervation. The reduced acetylcholinesterase activity demonstrates the involvement of the cholinergic innervation in the stomach of chronic chagasic patients. There was no correlation between number of neurons, sensitivity to cholinergic drugs and acetylcholinesterase activity in the gastric musculature of chagasic and non-chagasic patients.
Asunto(s)
Acetilcolinesterasa/metabolismo , Enfermedad de Chagas/tratamiento farmacológico , Colinérgicos/farmacología , Músculo Liso/inervación , Plexo Mientérico/patología , Estómago/inervación , Acetilcolina/farmacología , Adulto , Carbacol/farmacología , Estudios de Casos y Controles , Recuento de Células , Enfermedad de Chagas/enzimología , Agonistas Colinérgicos/farmacología , Acalasia del Esófago/patología , Acalasia del Esófago/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Liso/efectos de los fármacos , Músculo Liso/enzimología , Neuronas/citología , Estómago/efectos de los fármacos , Estómago/enzimologíaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Rosmarinus officinalis L. is a plant used around the world for its properties to cure pain in several conditions, such as arthritic and abdominal pain or as an antispasmodic; however, there are no scientific studies demonstrating its spasmolytic activity. Therefore, the aim of the present study was to investigate the effect of an ethanol extract from Rosmarinus officinalis aerial parts and the possible mechanism involved by using rings from the isolated guinea pig ileum (IGPI). MATERIALS AND METHODS: The IGPI rings were pre-contracted with potassium chloride (KCl; 60 mM), acetylcholine (ACh; 1 × 10(-9) to 1 × 10(-5)M) or electrical field stimulation (EFS; 0.3 Hz of frequency, 3.0 ms of duration and 14 V intensity) and tested in the presence of the Rosmarinus officinalis ethanol extract (150, 300, 600 and 1 200 µg/mL) or a referenced smooth muscle relaxant (papaverine, 30 µM). In addition, the possible mechanism of action was analyzed in the presence of hexametonium (a ganglionic blocker), indomethacine (an inhibitor of prostaglandins), l-NAME (a selective inhibitor of the nitric oxide synthase) and nifedipine (a calcium channel blocker). RESULTS: Rosmarinus officinalis ethanol extract exhibited a significant and concentration-dependent spasmolytic activity on the contractions induced by KCl (CI(50) = 661.06 ± 155.91 µg/mL); ACh (CI(50) = 464.05 ± 16.85 µg/mL) and EFS (CI(50) = 513.72 ± 34.13 µg/mL). Spasmolytic response of Rosmarinus officinalis (600 µg/mL) was reverted in the presence of nifedipine 1 µM, but not in the presence of hexamethonium 0.5mM, indomethacine 1 µM or L-NAME 100 µM. CONCLUSION: The present results reinforce the use of Rosmarinus officinalis as antispasmodic in folk medicine. Moreover, it is demonstrated the involvement of calcium channels in this activity, but not the participation of nicotinic receptors, prostaglandins or nitric oxide.
Asunto(s)
Canales de Calcio/efectos de los fármacos , Íleon/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Parasimpatolíticos/farmacología , Extractos Vegetales/farmacología , Rosmarinus , Animales , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio/metabolismo , Agonistas Colinérgicos/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Etanol/química , Bloqueadores Ganglionares/farmacología , Cobayas , Íleon/inervación , Íleon/metabolismo , Masculino , Músculo Liso/inervación , Músculo Liso/metabolismo , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Parasimpatolíticos/química , Parasimpatolíticos/aislamiento & purificación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Plantas Medicinales , Rosmarinus/química , Solventes/químicaRESUMEN
AIMS: Association between arterial hypertension and urinary bladder dysfunction has been reported in humans and spontaneously hypertensive rats. However, no study exists evaluating the bladder dysfunction in conditions of renovascular hypertension. The purpose of this study was to characterize the bladder dysfunction in two kidney-one clip (2K-1C) hypertensive rats. METHODS: A silver clip was placed around the renal artery of male Wistar rats. After 8 weeks, cystometric study, concentration-response curves to contractile and relaxant agents, frequency-dependent contractions, histomorphometry, muscarinic M(2) /M(3) mRNA expression and cyclic AMP measurements were performed. RESULTS: 2K-1C rats showed enhanced bladder volume, wall thickness and smooth muscle density. 2K-1C rats also exhibited increases in bladder capacity and non-void contractions, and decreases in the inter-contraction intervals. In isolated detrusor smooth muscle (DSM), contractions to carbachol and electrical-field stimulation (EFS) were significantly greater in 2K-1C rats. The Rho-kinase inhibitor Y27632 (10 µM) significantly reduced the carbachol-induced contractions in SHAM and 2K-1C rats, but DSM remained overactive in 2K-1C rats in presence of Y27632. Concentration-dependent contractions to the P2X receptor agonist α,ß-methylene ATP, KCl and extracellular Ca(2+) did not change between SHAM and 2K-1C groups. In 2K-1C rats, isoproterenol, metaproterenol and BRL 37-344 (non-selective, ß(2) - and ß(3) -selective adrenoceptor agonists, respectively) produced significantly lower relaxations and decreased cAMP levels, whereas relaxant responses to sodium nitroprusside and BAY 41-2272 remained unchanged. Muscarinic M(3) mRNA expression receptors were higher in 2K-1C group. CONCLUSIONS: Renovascular hypertensive rats exhibit bladder dysfunction that involves tissue remodeling and enhanced muscarinic M(3) -mediated contractions associated with reduced ß-adrenoceptor-mediated signal transduction.
Asunto(s)
Hipertensión Renovascular/complicaciones , Contracción Muscular , Relajación Muscular , Músculo Liso/fisiopatología , Enfermedades de la Vejiga Urinaria/etiología , Vejiga Urinaria/fisiopatología , Agonistas Adrenérgicos beta/farmacología , Animales , Agonistas Colinérgicos/farmacología , AMP Cíclico/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Hipertensión Renovascular/fisiopatología , Masculino , Contracción Muscular/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/inervación , Músculo Liso/metabolismo , Músculo Liso/patología , Fármacos Neuromusculares/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Agonistas del Receptor Purinérgico P2X/farmacología , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptor Muscarínico M3/genética , Transducción de Señal , Factores de Tiempo , Regulación hacia Arriba , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/inervación , Vejiga Urinaria/metabolismo , Vejiga Urinaria/patología , Enfermedades de la Vejiga Urinaria/metabolismo , Enfermedades de la Vejiga Urinaria/patología , Enfermedades de la Vejiga Urinaria/fisiopatología , Urodinámica , Quinasas Asociadas a rho/antagonistas & inhibidoresRESUMEN
In the resting state, motor neurons continuously release ACh through quantal and non-quantal mechanisms, the latter through vesicular ACh transporter (VAChT) and choline transporter (ChT). Although in skeletal muscle these mechanisms have been extensively studied, the non-quantal release (NQR) from parasympathetic neurons of airway smooth muscle has not been described. Here we corroborated that the organophosphate paraoxon (acetylcholinesterase inhibitor) induced a contraction blocked by atropine (muscarinic antagonist) in guinea-pig tracheal rings. This contraction was not modified by two blockers of evoked quantal release, tetrodotoxin (voltage-dependent Na(+) channel blocker) and ω-conotoxin GVIA (N-type Ca(2+) channel blocker), nor by the nicotinic blocker hexamethonium, suggesting that acetylcholine NQR could be responsible of the paraoxon-induced contraction. We confirmed that tetrodotoxin, and to some extent -conotoxin, abolished the evoked quantal ACh release induced by electrical field stimulation. Hemicholinium-3 (ChT inhibitor), but not vesamicol (VAChT inhibitor), caused a concentration-dependent inhibition of the response to paraoxon. The highest concentration of hemicholinium-3 left â¼75% of the response to electrical field stimulation, implying that inhibition of paraoxon-induced contraction was not due to depletion of neuronal vesicles. Non-neuronal sources of ACh released through organic cation transporters were discarded because their inhibition by quinine or corticosterone did not modify the response to paraoxon. Calcium-free medium abolished the effect of paraoxon, and NiCl(2), 2-aminoethyl diphenyl-borate and SKF 96365 partly inhibited it, suggesting that non-specific cation channels were involved in the acetylcholine NQR. We concluded that a Ca(2+)-dependent NQR of ACh is present in cholinergic nerves from guinea-pig airways, and that ChT is involved in this phenomenon.
Asunto(s)
Acetilcolina/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Tráquea/metabolismo , Proteínas de Transporte Vesicular de Acetilcolina/metabolismo , Animales , Atropina/farmacología , Calcio/metabolismo , Proteínas de Transporte de Catión/metabolismo , Inhibidores de la Colinesterasa/farmacología , Estimulación Eléctrica , Cobayas , Hemicolinio 3/farmacología , Hexametonio/farmacología , Masculino , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/inervación , Músculo Liso/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Organofosfatos/farmacología , Paraoxon/farmacología , Piperidinas/farmacología , Tetrodotoxina/farmacología , Tráquea/efectos de los fármacos , Tráquea/inervación , omega-Conotoxina GVIA/farmacologíaRESUMEN
Lesões na inervação do trato urinário inferior ocasionado por traumatismo raquimedular afetam geralmente o músculo detrusor e o esfíncteres uretrais. Estas alterações acarretam problemas basicamente de incontinência urinária e aumento da pressão intravesical, decorrente deste traumatismo, trazendo consequências para o funcionamento do sistema urinário superior. Quantificar os elementos fibrosos da matriz extracelular e fibras musculares das bexigas neurogênicas hiper-reflexas comparando-as com bexigas normais. Foram utilizadas 6 amostras de bexigas neurogênicas de indivíduos que foram submetidos a cirurgia de reparação por cistoenteroplastia realizados pelo serviço de urologia do Hospital Municipal Souza Aguiar, estas amostras foram fixadas imediatamente em solução tamponada de formalina a 10%. O controle com amostras iguais as do estudo extraída de cadáveres cuja causa morte não relacionava-se ao sistema urogenital macroscópicamente. O material foi submetido as seguintes técnicas histoquímicas: H&E, van Gieson e Resorcina Fucsina resorcina de Weigert com prévia oxidação pela oxona. Imunohistoquímica: anti-elastina. A observação dos cortes corados pelo van Gieson demonstrou uma diminuição significativa do músculo liso de 13% e aumento do colágeno em 72% e as fibras do sistema elástico um aumento de 101%. Conclusão. Nas bexigas neurogênicas hiper-reflexas o músculo detrusor e os elementos fibrosos da matriz foram profundamente modificados. As fibras do sistema elástico foram as mais afetadas.
Lesions on lower urinary tract innervations caused by spinal cord injuries usually affect the detrusor muscle and urethral sphincter. Beside the smooth muscle fibers the collagen fibers and elastic system fibers, fibrous components of the extracellular matrix of the bladder wall, are strongly related to vesicle bladder compliance. For this reason the aim of this work is to quantify the fibrous elements of the extracellular matrix and muscle fibers of the neurogenic bladder hyperreflexia. Samples of neurogenic bladder were obtained from six men who had previously undergone surgical repair. The control group samples (n=6) were similarly obtained from patients whose deaths were not related to the urogenital system. The samples were stained using the following histochemical techniques: H&E, Van Gieson, Weigert and Sirius Red. Sections stained with Sirius Red were observed under polarization light microscopy to characterize possible different kinds of collagen. Immunohistochemical technique was used to characterize and quantify the elastic system fibers. Quantification analysis was performed by stereological methods. An increase of 72% of the collagen was observed. Nevertheless, the most significant difference observed was the raising of 101% of the elastic system fibers. Contrary the smooth muscle fibers showed a decrease of 13%. In the neurogenic bladder with detrusor hyperreflexia the fibrous elements of the extracellular matrix and smooth muscle fibers were greatly modified. The elastic system fibers seem to be the most affected in this disease.
Asunto(s)
Humanos , Masculino , Femenino , Vejiga Urinaria Neurogénica/etiología , Vejiga Urinaria/inervación , Vejiga Urinaria/lesiones , Inmunohistoquímica , Incontinencia Urinaria/etiología , Músculo Liso/citología , Músculo Liso/inervación , Traumatismos de la Médula Espinal/complicaciones , Vesícula Biliar/fisiopatologíaRESUMEN
PURPOSE: To assess in vitro the correlation between the number of neurons and the sensitivity to cholinergic drugs and acetylcholinesterase activity in chagasic patients. METHODS: A 3x1 cm strip of the muscle layer of the anterior part of the stomach, always close to the angular incisure, was removed from 10 chronic chagasic patients (6 men) submitted to megaesophagus or megacolon surgery and from 10 non-chagasic patients (4 men) submitted to other types of surgery (control group), aged on average 52.3 and 50.1 years, respectively, for histological and pharmacological studies. The action of cholinergic drugs was investigated in isolated preparations according to the superfusion method of Ferreira and Costa, and acetylcholinesterase activity was determined by the method of Ellman. For neuron count, the strips were cut into 8 µm sections according to the method standardized by Alcântara. RESULTS: There was a difference in number of neurons between the chagasic (5,6) and control (7,3) groups. Acetylcholinesterase activity, in moles of hydrolyzed substrate per minute per gram tissue, was reduced in chagasic patients (4,32) compared to the controls (7,30). No hypersensitivity of the gastric musculature to cholinergic drugs was detected, with a reduced maximum response to carbachol and betanechol in the chagasic group. CONCLUSIONS: The reduction of neurons in the myenteric plexus of the stomach of chronic chagasic patients can be demonstrated even in the absence of clinical chagasic gastropathy. The hypersensitivity of the gastric musculature to cholinergic drugs probably depends on intense denervation. The reduced acetylcholinesterase activity demonstrates the involvement of the cholinergic innervation in the stomach of chronic chagasic patients. There was no correlation between number of neurons, sensitivity to cholinergic drugs and acetylcholinesterase activity in the gastric musculature of chagasic and non-chagasic patients.
OBJETIVO: Avaliar in vitro a correlação entre o número de neurônios e a sensibilidade a drogas colinérgicas e a atividade da acetilcolinesterase em pacientes chagásicos. MÉTODOS: Em 10 pacientes chagásicos crônicos (6 homens) submetidos à cirurgia de megaesôfago ou de megacólon e em 10 pacientes não chagásicos (4 homens) submetidos a outros tipos de cirurgia (grupo controle), respectivamente com idade média de 52,3 e 50,1 anos, retirou-se uma tira de 3x1 cm da camada muscular da parede anterior do estômago, sempre junto á cisura angular, que serviu para os estudos histológicos e farmacológicos. A ação de drogas colinérgicas foi feita em preparação isolada de acordo com o método de superfusão de Ferreira e Costa, e a determinação da atividade da acetilcolinesterase pelo método de Ellman. Para a contagem de neurônios a tira muscular foi submetida a cortes de 8 micra segundo método padronizado por Alcântara. RESULTADOS: Houve diferença do número de neurônios entre os grupos chagásico (5,6) e controle (7,3). A atividade da acetilcolinesterase mostrou-se diminuída nos chagásicos (4,32) expressa como número de moles do substrato hidrolisado por minuto por grama de tecido, em relação aos controles (7,30). Não se encontrou hipersensibilidade da musculatura gástrica a drogas colinérgicas, encontrando-se inclusive efeito máximo reduzido ao carbacol e betanecol no grupo chagásico. CONCLUSÕES: A redução de neurônios no plexo mioentérico do estômago de pacientes chagásicos crônicos pode ser demonstrada mesmo na ausência de gastropatia chagásica clínica. A hipersensibilidade da musculatura gástrica a drogas colinérgicas provavelmente depende de desnervação intensa. A redução da atividade da acetilcolinesterase demonstra o comprometimento da inervação colinérgica no estômago de pacientes chagásicos crônicos. Não houve correlação entre número de neurônios, sensibilidade a drogas colinérgicas e atividade da acetilcolinesterase na musculatura gástrica de pacientes chagásicos ou não chagásicos.
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Acetilcolinesterasa/metabolismo , Enfermedad de Chagas/tratamiento farmacológico , Colinérgicos/farmacología , Músculo Liso/inervación , Plexo Mientérico/patología , Estómago/inervación , Acetilcolina/farmacología , Estudios de Casos y Controles , Recuento de Células , Carbacol/farmacología , Enfermedad de Chagas/enzimología , Agonistas Colinérgicos/farmacología , Acalasia del Esófago/patología , Acalasia del Esófago/cirugía , Músculo Liso/efectos de los fármacos , Músculo Liso/enzimología , Neuronas/citología , Estómago/efectos de los fármacos , Estómago/enzimologíaRESUMEN
AIM OF THE STUDY: Mentha piperita is a plant popularly known in Brazil as "hortelã-pimenta" whose essential oil is used in folk medicine for its anti-inflammatory, antispasmodic, expectorant actions and anti-congestive. Here, it was investigated the effect of Mentha piperita essential oil (peppermint oil) in rat tracheal rings along with its mechanism of action. MATERIALS AND METHODS: Tracheal tissue from male Wistar rats (250-300 g) were used. Peppermint oil was added in cumulative concentrations [1-300 microg/ml] to the tissue basal tonus or pre-contracted by carbachol [10 microM] at 10 min intervals, incubated or not with indomethacin [10 microM], L-N-metyl-nitro-arginine [100 microM], hexamethonium [500 microM], or tetraethylammonium [5 mM]. RESULTS: Peppermint oil [100 and 300 microg/ml] inhibited the contractions induced by carbachol, which was reversed by indomethacin, L-N-metyl-nitro-arginine and hexamethonium, but not by tetraethylammonium. These data suggest the participation of prostaglandin E(2), nitric oxide and autonomic ganglions in the peppermint oil relaxant effect and may be correlated with its popular use in respiratory diseases. CONCLUSIONS: Peppermint oil exhibited antispasmodic activity on rat trachea involving prostaglandins and nitric oxide synthase.
Asunto(s)
Mentha piperita , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Parasimpatolíticos/farmacología , Aceites de Plantas/farmacología , Tráquea/efectos de los fármacos , Animales , Inhibidores de la Ciclooxigenasa/farmacología , Dinoprostona/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Ganglios Autónomos/efectos de los fármacos , Bloqueadores Ganglionares/farmacología , Técnicas In Vitro , Masculino , Músculo Liso/inervación , Músculo Liso/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Aceites de Plantas/química , Ratas , Ratas Wistar , Tráquea/inervación , Tráquea/metabolismoRESUMEN
We tested the hypothesis that the basal release of nitric oxide (NO) from endothelial cells modulates contractile activity in the corpus cavernosum (CC) via inhibition of the RhoA/Rho-kinase signaling pathway. Cavernosal strips from wild-type (WT), endothelial nitric-oxide synthase knockout [eNOS(-/-)], and neuronal nitric-oxide synthase knockout [nNOS(-/-)] mice were mounted in myographs, and isometric force was recorded. mRNA and protein expression of key molecules in the RhoA/Rho-kinase pathway were analyzed by real-time polymerase chain reaction and Western blot, respectively. The cGMP levels were determined. The Rho-kinase inhibitors (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) and (S)-(+)-2-methyl-1-[(4-methyl-5-isoquinolinyl)sulfonyl] homopiperazine (H-1152) reduced cavernosal contractions evoked by phenylephrine or electrical field stimulation (EFS) in a concentration-dependent manner, although this inhibition was less effective in tissues from eNOS(-/-) mice. Y-27632 enhanced relaxations induced by sodium nitroprusside, EFS, and NO (administered as acidified NaNO2) without affecting the cGMP content of the cavernosal strips. This enhancement was less prominent in CC from eNOS(-/-). The protein expression of RhoA, Rho-guanine dissociation inhibitor, and Rho-kinase beta did not differ among the strains. However, in eNOS(-/-) CC, the protein expression of Rho-kinase alpha and both mRNA and protein expression of p115-Rho-associated guanine exchange factor (RhoGEF), PDZ-RhoGEF, and leukemia-associated RhoGEF were up-regulated. Phosphorylation of MYPT1 at Thr696 was higher in tissues from eNOS(-/-) mice. A high concentration of Y-27632 significantly enhanced NO release in CC stimulated by EFS. These results suggest a basal release of NO from endothelial cells, which inhibits contractions mediated by the RhoA/Rho-kinase pathway and modulates the expression of proteins related to this pathway in mouse CC. It indicates that endothelial integrity is essential to the maintenance of erectile function.
Asunto(s)
Óxido Nítrico Sintasa de Tipo III/genética , Óxido Nítrico Sintasa de Tipo I/genética , Pene/enzimología , Proteínas de Unión al GTP rho/fisiología , Quinasas Asociadas a rho/fisiología , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/análogos & derivados , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina/farmacología , Amidas/farmacología , Animales , GMP Cíclico/metabolismo , Endotelio Vascular/metabolismo , Técnicas In Vitro , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Contracción Muscular , Relajación Muscular , Músculo Liso/irrigación sanguínea , Músculo Liso/inervación , Músculo Liso/fisiología , Óxido Nítrico/metabolismo , Pene/irrigación sanguínea , Pene/inervación , Piridinas/farmacología , Transducción de Señal , Especificidad de la Especie , Regulación hacia Arriba , Proteínas de Unión al GTP rho/biosíntesis , Quinasas Asociadas a rho/antagonistas & inhibidores , Quinasas Asociadas a rho/biosíntesis , Proteína de Unión al GTP rhoARESUMEN
Relaxation of gastrointestinal smooth muscle caused by release of non-adrenergic non-cholinergic (NANC) transmitters from enteric nerves occurs in several physiologic digestive reflexes. Likely candidate NANC inhibitory agents include nitric oxide (NO), adenosine triphosphate (ATP), vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating peptide (PACAP), carbon monoxide (CO), protease-activated receptors (PARs), hydrogen sulfide (H2S), neurotensin (NT) and beta-nicotinamide adenine dinucleotide (beta-NAD). Multiple NANC transmitters work in concert, are pharmacologically coupled and are closely coordinated. Individual contribution varies regionally in the gastrointestinal tract and between species. NANC inhibition of gastrointestinal smooth muscle involves several intracellular mechanisms, including increase of cyclic guanosine monophosphate (cGMP), increase of cyclic adenosine monophosphate (cAMP) and hyperpolarization of the cell membrane via direct or indirect activation of potassium ion (K+) channels.
Asunto(s)
Adrenérgicos , Colinérgicos , Tracto Gastrointestinal/fisiología , Membranas Intracelulares/fisiología , Músculo Liso/fisiología , Inhibición Neural/fisiología , Animales , AMP Cíclico/biosíntesis , AMP Cíclico/fisiología , GMP Cíclico/biosíntesis , GMP Cíclico/fisiología , Tracto Gastrointestinal/inervación , Tracto Gastrointestinal/metabolismo , Humanos , Membranas Intracelulares/metabolismo , Músculo Liso/inervación , Músculo Liso/metabolismo , Neurotransmisores/biosíntesis , Neurotransmisores/metabolismo , Neurotransmisores/fisiología , Canales de Potasio/metabolismo , Canales de Potasio/fisiologíaRESUMEN
In mammals, at least five different muscarinic acetylcholine receptor subtypes (mAChRs; M(1)-M(5)) are known to be widely expressed and distributed in different tissues from different species. They mediate distinct physiological functions according to their location and receptor subtype. Multiple events are associated with the regulation of intracellular signaling by mAChRs, and a coordinated balance of the molecular mechanisms governing receptor signaling, desensitization, resensitization, and mitogenic signaling is known to occur in various cell types. Most of the actions of acetylcholine (ACh) in the male reproductive tract are induced by its effects on mAChRs, but the role of specific mAChR subtypes on male reproductive function and fertility are still not well understood. The rat efferent ductules and epididymis are androgen-dependent tissues of the male reproductive tract, with important roles in the process to form a viable and fertile sperm. In the present study, aspects of the expression, localization, and potential function of mAChR subtypes in rat efferent ductules and epididymis are reviewed. Furthermore, evidences for the implication of mAChRs in the regulation of protein synthesis and secretion in these tissues are presented. Taken together, the studies contribute to our understanding about physiological aspects of mAChR and mechanisms by which the cholinergic system affects male reproduction.
Asunto(s)
Acetilcolina/metabolismo , Epidídimo/metabolismo , Receptores Muscarínicos/metabolismo , Testículo/metabolismo , Andrógenos/metabolismo , Animales , Epidídimo/citología , Epidídimo/inervación , Células Epiteliales/fisiología , Masculino , Músculo Liso/inervación , Músculo Liso/fisiología , Biosíntesis de Proteínas/fisiología , Subunidades de Proteína/metabolismo , Ratas , Espermatogénesis/fisiología , Testículo/citología , Testículo/inervaciónRESUMEN
Calomys callosus is a wild, native forest rodent found in South America. In Brazil, this species has been reported to harbour the parasitic protozoan Trypanosoma cruzi. The ganglionated plexus of this species was studied using whole-mount preparations of trachea that were stained using histological and histochemical methods. The histological methods were used to determine the position of the ganglia with respect to the trachea muscle and to determine the presence of elastic and collagen fibers. The histochemical method of NADH-diaphorase was used for morphometric evaluations of the plexus. The tracheal plexus lies exclusively over the muscular part of the organ, dorsal to the muscle itself. It varies in pattern and extent between animals. The average number of neurons was 279 and the cellular profile area ranged from 38.37 microm2 to 805.89 microm2. Acetylcholinesterase (AChE) histochemistry verified that both ganglia and single neurons lie along nerve trunks and are reciprocally interconnected with the plexus. Intensely AChE-reactive neurons were found to be intermingled with poorly reactive ones. Two longitudinal AChE-positive nerve trunks were also observed and there was a diverse number of ganglia along the intricate network of nerves interconnecting the trunks. A ganglion capsule of collagen and elastic fibers surrounding the neurons was observed. Under polarized light, the capsule appeared to be formed by Type I collagen fibers.
Asunto(s)
Vías Autónomas/citología , Ganglios Autónomos/citología , Neuronas/citología , Roedores/anatomía & histología , Tráquea/inervación , Acetilcolina/metabolismo , Acetilcolinesterasa/análisis , Acetilcolinesterasa/metabolismo , Animales , Vías Autónomas/enzimología , Recuento de Células , Tamaño de la Célula , Colágeno/metabolismo , Colágeno/ultraestructura , Tejido Elástico/metabolismo , Tejido Elástico/ultraestructura , Ganglios Autónomos/enzimología , Histocitoquímica , Masculino , Músculo Liso/inervación , Músculo Liso/metabolismo , NAD/análisis , NAD/metabolismo , Neuronas/enzimología , Roedores/fisiología , Células Satélites Perineuronales/citología , Especificidad de la Especie , Tráquea/fisiologíaRESUMEN
Disorders of swallowing and gastrointestinal motility are prominent nonmotor manifestations of Parkinson disease (PD). Motility of the gut is controlled both by extrinsic inputs from the dorsal motor nucleus of the vagus (DMV) and paravertebral sympathetic ganglia and by local reflexes mediated by intrinsic neurons of the enteric nervous system (ENS). Both the ENS and the DMV are affected by Lewy body pathology at early stages of PD. This early involvement provides insights into the pathophysiology of gastrointestinal dysmotility in this disorder and may constitute an important step in the etiopathogenesis of Lewy body disease.
Asunto(s)
Tracto Gastrointestinal/inervación , Enfermedad de Parkinson/fisiopatología , Canal Anal/inervación , Sistema Nervioso Entérico/fisiopatología , Trastornos de la Motilidad Esofágica/fisiopatología , Vaciamiento Gástrico/fisiología , Enfermedades Gastrointestinales/fisiopatología , Motilidad Gastrointestinal/fisiología , Humanos , Enfermedad por Cuerpos de Lewy/fisiopatología , Bulbo Raquídeo/fisiopatología , Músculo Esquelético/inervación , Músculo Liso/inervación , Red Nerviosa/fisiopatología , Sistema Nervioso Parasimpático/fisiopatología , Médula Espinal/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Nervio Vago/fisiopatologíaRESUMEN
We evaluated changes involving the myenteric neurons of the guinea pig after different times of ischemia in situ followed by superfusion in vitro. Intestinal ischemia was produced by clamping the superior mesenteric artery and maintaining it for 5, 10, 20, 40, 80, or 160 min. Myenteric plexus-longitudinal muscle preparations from ischemic and non-ischemic portions, obtained from the same guinea pig, were dissected and mounted in organ baths containing Krebs bicarbonate solution at 37 degrees C, gassed with 95% O(2) and 5% CO(2). After 2 h of superfusion, ischemic and non-ischemic strips were removed, immersed in a fixative solution, and processed for light and electron microscopy. We found that ultrastructural neuronal changes, which corresponded with light microscopy findings, developed over time. Some structural changes started after 10 min of ischemia, including cell swelling, chromatin clumping, vacuolization, and disruption of protoplasmic and mitochondrial membranes. Smooth muscle cells changes paralleled those observed in the myenteric neurons, but were evidenced until 40 min of ischemia were completed. These results show that ischemia produces acute time-dependent structural changes in the guinea-pig small intestine, and that affected cells exhibit primarily morphological changes characteristic of necrosis.
Asunto(s)
Íleon/ultraestructura , Isquemia/patología , Oclusión Vascular Mesentérica/complicaciones , Músculo Liso/ultraestructura , Plexo Mientérico/ultraestructura , Neuronas/ultraestructura , Animales , Constricción , Modelos Animales de Enfermedad , Cobayas , Íleon/irrigación sanguínea , Íleon/inervación , Íleon/fisiopatología , Isquemia/etiología , Isquemia/fisiopatología , Masculino , Arterias Mesentéricas/cirugía , Oclusión Vascular Mesentérica/patología , Oclusión Vascular Mesentérica/fisiopatología , Contracción Muscular , Músculo Liso/irrigación sanguínea , Músculo Liso/inervación , Músculo Liso/fisiopatología , Necrosis , Perfusión/métodos , Factores de TiempoRESUMEN
The enteric nervous system comprises two major systems: the submucosal and the myenteric plexus. The aim of this study was to describe the myenteric plexus from three strains of spontaneous diabetic rats from the histological point of view. Samples of small intestine and of proximal and distal colon were obtained fom three spontaneous diabetic rats i.e., eSS, eSMT, beta strains and 1-year old Wistar rats. Specimens were stained with NADH (beta-nicotinamide adenine dinucleotide, reduced form) histochemical technique and examined with light microscope. Microscopically little modifications in mesh-like structure of intestinal Auerbach's plexus from eSS were detected in comparison with Wistar rats samples. Intestinal plexus of eSMT and beta rats showed disruption of mesh-like structures, modifications in the slightly colored background (smooth muscle) and augmented vascularization. Small intestine and colon are affected. In short: In our spontaneously diabetic rat models, mesh-like structure of Auerbach's plexus is strain dependent.