RESUMEN
(-)-Carvone, a ketone monoterpene, is the main component of essential oils from several medicinal plants and has been reported to have anti-arthriric, anticonvulsive, antidiabetic, anti-inflammatory, anticancer, and immunomodulatory effects. Therefore, this study aimed to investigate the spasmolytic activity of (-)-carvone in rodent models. The isolated virgin rat uterus was mounted in an organ bath apparatus, and the relaxing effect of ( -)-carvone and its mechanism of action were evaluated in tonic contractions induced by carbachol, KCl, PGF2α, or oxytocin. The animal model of primary dysmenorrhea was replicated with the injection of estradiol benzoate in female mice for three consecutive days, followed by intraperitoneal administration of oxytocin. Non-clinical acute toxicity evaluation was also performed. (-)-Carvone potency and effectiveness were larger in carbachol (pEC50 = 5.41 ± 0.14 and Emax = 92.63 ± 1.90% at 10-3 M) or oxytocin (pEC50 = 4.29 ± 0.17 and Emax = 86.69 ± 1.56% at 10-3 M) contractions. The effect of ( -)-carvone was altered in the presence of 4-aminopyridine, glibenclamide, L-NAME, or methylene blue. Mice pre-treated with (-)-carvone at a dose of 100 mg/kg showed a significant reduction in the number of writhing after oxytocin administration. No toxicity was observed after oral administration of 1 g/kg ( -)-carvone. Taken together, we showed that (-)-carvone reduced writhing by a spasmolytic effect, probably through the participation of KV and KATP channels and the nitric oxide pathway.
Asunto(s)
Monoterpenos Ciclohexánicos , Monoterpenos , Oxitocina , Útero , Animales , Oxitocina/farmacología , Femenino , Monoterpenos Ciclohexánicos/farmacología , Ratones , Útero/efectos de los fármacos , Monoterpenos/farmacología , Contracción Uterina/efectos de los fármacos , Ratas , Ratas Wistar , Parasimpatolíticos/farmacología , Relajación Muscular/efectos de los fármacos , Carbacol/farmacologíaRESUMEN
Several reports have demonstrated that depressive disorder is related to somatic symptoms including gastrointestinal or genitourinary alterations. The pathophysiological mechanisms underlying the gastrointestinal or genitourinary alterations associated with the depression are still not fully understood. Therefore, this study aimed to evaluate the motor activity of gastrointestinal (fundus of stomach and duodenum) and genitourinary tract (bladder) in a stress-based animal model of depression. Adult male mice were submitted to uncontrollable and unpredictable stress (learned helplessness model), controllable stress and non-stressful situations (control). Then, animals were euthanized and the fundus of stomach, duodenum segments or whole bladder were isolated and mounted in a standard organ bath preparation. We evaluated the contractile effects induced by KCl 80 mM for 5 min or carbachol (acetylcholine receptor agonist). The relaxant effects of isoproterenol (ß-adrenoceptor agonist) were also checked. Animals submitted to the learned helplessness model developed a helpless (depressive-like behavior) or resilient (does not exhibit depressive-like behavior) phenotype. The contractions induced by carbachol were diminished in fundus of stomach isolated from helpless and resilient animals. The isoproterenol-induced fundus of stomach relaxation was reduced in resilient but not helpless mice. The contractions/relaxation of duodenum segments isolated from helpless or resilient animals were not altered. Both helpless and resilient animals showed an increase in the bladder contractions induced by carbachol while the relaxant effects of isoproterenol were reduced when compared to control. Conversely, mice underwent a controllable stress situation did not exhibit alterations in the fundus of stomach or duodenum contraction/relaxation induced by pharmacological agents although a decrease in the bladder contraction induced by carbachol was found. In conclusion, incontrollable and unpredictable stress and not depressive phenotype (helpless animals) or controllable stress could be related to the alterations in motor activity of the fundus of stomach and bladder.
Asunto(s)
Depresión , Vejiga Urinaria , Ratones , Masculino , Animales , Carbacol/farmacología , Isoproterenol/farmacología , Estómago/fisiología , Contracción Muscular/fisiología , DuodenoRESUMEN
PURPOSE: This study aimed to assess the possible healing effect of combination treatment with a hydrogen sulfide (H2S) donor, sodium hydrosulfide (NaHS) plus tadalafil on partial bladder outlet obstruction (PBOO)-induced bladder dysfunction. MATERIALS AND METHODS: A total of 75 male Sprague-Dawley rats aged 10-wk and 300-350g were divided into five groups; control; PBOO; PBOO+NaHS (5.6mg/kg/day, i.p., 6-wk); PBOO+tadalafil (2mg/kg/day, oral, 6-wk) and PBOO+NaHS+tadalafil. PBOO was created by partial urethral ligation. 6 weeks after obstruction, the in vitro contractile responses of the detrusor muscle and Western blotting, H2S and malondialdehyde assay were performed in bladder tissues. RESULTS: There was an increase in bladder weight(p<0.001) and a decrease in contractile responses to KCL(p<0.001), carbachol(p<0.01), electrical field stimulation(p<0.05) and ATP (p<0.001) in the detrusor smooth muscle of obstructed rats which was normalized after the combination treatment. Cystathionine γ-lyase and cystathionine ß-synthase, and nuclear factor kappa B protein levels did not significantly differ among groups. The obstruction induced decrement in 3-mercaptopyruvate sulfur transferase protein expression(p<0.001) and H2S levels(p<0.01) as well as increment in protein expressions of neuronal nitric oxide synthase (NO, p<0.001), endothelial NOS (p<0.05), inducible NOS(p<0.001), hypoxia-inducible factor 1-alpha (p<0.01), and malondialdehyde levels (p<0.01), when combined treatment entirely normalized. CONCLUSIONS: Combination therapy has beneficial effects on bladder dysfunction via regulating both H2S and nitric oxide pathways as well as downregulation of oxidative stress and hypoxia. The synergistic effect of H2S and nitric oxide is likely to modulate bladder function, which supports the combined therapy for enhancing clinical outcomes in men with BPH/LUTS.
Asunto(s)
Sulfuro de Hidrógeno , Obstrucción del Cuello de la Vejiga Urinaria , Adenosina Trifosfato/metabolismo , Adenosina Trifosfato/farmacología , Adenosina Trifosfato/uso terapéutico , Animales , Carbacol/metabolismo , Carbacol/farmacología , Carbacol/uso terapéutico , Cistationina betasintasa/metabolismo , Cistationina betasintasa/farmacología , Cistationina betasintasa/uso terapéutico , Cistationina gamma-Liasa/metabolismo , Cistationina gamma-Liasa/farmacología , Cistationina gamma-Liasa/uso terapéutico , Sulfuro de Hidrógeno/metabolismo , Sulfuro de Hidrógeno/farmacología , Sulfuro de Hidrógeno/uso terapéutico , Hipoxia/tratamiento farmacológico , Hipoxia/metabolismo , Factor 1 Inducible por Hipoxia/metabolismo , Factor 1 Inducible por Hipoxia/farmacología , Factor 1 Inducible por Hipoxia/uso terapéutico , Masculino , Malondialdehído , FN-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo I/metabolismo , Estrés Oxidativo , Ratas , Ratas Sprague-Dawley , Sulfuros , Azufre/metabolismo , Azufre/farmacología , Azufre/uso terapéutico , Tadalafilo/farmacología , Tadalafilo/uso terapéutico , Transferasas/metabolismo , Transferasas/farmacología , Transferasas/uso terapéutico , Vejiga Urinaria , Obstrucción del Cuello de la Vejiga Urinaria/tratamiento farmacológicoRESUMEN
Caffeic acid is a phenolic compound widely found in commonly consumed foods such as pears, apples and coffee, and is pharmacologically known for its antioxidant, anti-inflammatory and anti-asthmatic properties. However, its relaxant activity in the aorta, uterus and ileum smooth muscle has not been investigated. This study aimed to comparatively evaluate the effect of caffeic acid on smooth muscle from different organs (aorta, uterus and ileum), and the contractions of this different organ were induced by different agonists. The organ bath technique was used, where the organs were placed in different cuvettes with 10 mL of Tyrode solution for 1 h to stabilize, then, myometrial, intestinal strip and aortic ring contractions were evoked using different contractile agonists (KCl 60 mM, PHE 0.1 µM, OT 10-2 IU/mL, CCh 10-6 M and BaCl2 0.1-30 mM); increasing concentrations of caffeic acid (0.03-7 mM) were administered in the experimental preparations. In the presence of KCl (60 mM), caffeic acid caused relaxations with the following EC50 values: 2.7 ± 0.26 mM/mL (aorta), 5.7 ± 0.71 mM/mL (uterus) and 2.1 ± 0.39 mM/mL (ileum). When in the presence of different agonists, PHE (0.1 µM) for the aorta, OT (10-2 IU/mL) for the uterus and CCh (10-6 M) for the ileum, caffeic acid caused relaxations with EC50 values of: 2.7 ± 0.31 mM/mL; 2.2 ± 0.34 mM/mL and 2.0 ± 0.28 mM/mL, respectively. The inhibitory effect of caffeic acid on serotonergic (aorta and uterus) and muscarinic receptors (uterus and ileum), as well as its possible involvement with L-type Ca2+ channels, was also observed. This study reports the pharmacological characterization of caffeic acid on smooth muscle from different organs, for which caffeic acid was more potent in the ileum. A diverse understanding of its performance as a possible therapeutic product is attributed to its relaxant effect.
Asunto(s)
Aorta/fisiología , Ácidos Cafeicos/farmacología , Evaluación Preclínica de Medicamentos , Íleon/fisiología , Músculo Liso/fisiología , Fenoles/farmacología , Útero/fisiología , Animales , Aorta/efectos de los fármacos , Ácidos Cafeicos/química , Canales de Calcio Tipo L/metabolismo , Carbacol/farmacología , Femenino , Íleon/efectos de los fármacos , Masculino , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Oxitocina/farmacología , Fenoles/química , Fenilefrina/farmacología , Cloruro de Potasio , Ratas Wistar , Útero/efectos de los fármacosRESUMEN
Here, we described the effects of obesity induced by high-calorie diet and its treatment with exenatide, an anti-diabetogenic and potential anti-obesogenic drug derived from the venom of the Gila monster Heloderma suspectum, on the affinity, density, subtypes and intracellular signaling pathways linked to activation of muscarinic acetylcholine receptors (mAChRs) in rat hippocampus. Male Wistar rats were divided into three groups: control (CT), obese induced by high-calorie diet (DIO) and DIO treated with exenatide (DIOâ¯+â¯E). [3H]Quinuclidinyl benzilate specific binding analysis showed that the equilibrium dissociation constant (KD) did not differ among CT, DIO and DIOâ¯+â¯E, indicating that affinity is not affected by high-calorie diet or its treatment with exenatide. On the other hand, the density of mAChRs obtained in DIO animals was lower than that obtained from CT rats, and that DIOâ¯+â¯E restored the density of mAChRs. Immunoprecipitation assays reveal a decrease in the expression of M1 and M3 subtypes of DIO animals when compared with CT. Treatment with exenatide (DIOâ¯+â¯E) restored the expression of the two subtypes similar to obtained from CT. On the other hand, the M2, M4 and M5 mAChR subtypes expression did not differ among CT, DIO and DIOâ¯+â¯E. Carbacol caused a concentration-dependent increase in the accumulation of total [3H] inositol phosphate in CT, DIO and DIOâ¯+â¯E. However, the magnitude of the maximal response to carbachol was lower in DIO when compared with those obtained from CT and DIOâ¯+â¯E animals, which did not differ from each other. Our results indicate that obesity induced by high-calorie diet strongly influences the expression and intracellular signaling coupled to M1-M3 mAChR subtypes. The exenatide ameliorated these effects, suggesting an important role on hippocampal muscarinic cholinergic system. This action of obesity induced by high-calorie diet and its treatment with exenatide might be a key step mediating cellular events important for learning and memory.
Asunto(s)
Exenatida/uso terapéutico , Hipocampo/efectos de los fármacos , Obesidad/tratamiento farmacológico , Receptores Muscarínicos/efectos de los fármacos , Animales , Carbacol/farmacología , Ingestión de Energía , Exenatida/farmacología , Receptor del Péptido 1 Similar al Glucagón/fisiología , Hipocampo/fisiología , Masculino , Ratas , Ratas Wistar , Receptores Muscarínicos/fisiologíaRESUMEN
Intracerebroventricular (icv) injection of hydrogen peroxide (H2O2), a reactive oxygen species, or the blockade of catalase (enzyme that degrades H2O2 into H2O and O2) with icv injection of 3-amino-1,2,4-triazole (ATZ) reduces the pressor effects of angiotensin II also injected icv. In the present study, we investigated the effects of ATZ injected icv or intravenously (iv) on the pressor responses induced by icv injections of the cholinergic agonist carbachol, which similar to angiotensin II induces pressor responses that depend on sympathoexcitation and vasopressin release. In addition, the effects of H2O2 icv on the pressor responses to icv carbachol were also tested to compare with the effects of ATZ. Normotensive non-anesthetized male Holtzman rats (280-300 g, n = 8-9/group) with stainless steel cannulas implanted in the lateral ventricle were used. Previous injection of ATZ (5 nmol/1 µl) or H2O2 (5 µmol/1 µl) icv similarly reduced the pressor responses induced by carbachol (4 nmol/1 µl) injected icv (13 ± 4 and 12 ± 4 mmHg, respectively, vs. vehicle + carbachol: 30 ± 5 mmHg). ATZ (3.6 mmol/kg of body weight) injected iv also reduced icv carbachol-induced pressor responses (21 ± 2 mmHg). ATZ icv or iv and H2O2 icv injected alone produced no effect on baseline arterial pressure. The treatments also produced no significant change of heart rate. The results show that ATZ icv or iv reduced the pressor responses to icv carbachol, suggesting that endogenous H2O2 acting centrally inhibits the pressor mechanisms (sympathoactivation and/or vasopressin release) activated by central cholinergic stimulation.
Asunto(s)
Presión Sanguínea/efectos de los fármacos , Catalasa/farmacología , Hipertensión/fisiopatología , Amitrol (Herbicida)/farmacología , Angiotensina II , Animales , Carbacol/farmacología , Agonistas Colinérgicos/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Hipertensión/tratamiento farmacológico , Inyecciones Intraventriculares , Masculino , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno , Vasoconstrictores/farmacología , VasopresinasRESUMEN
BACKGROUND: Some studies have linked the use of paracetamol (PAR) with adverse effects like wheezing, exacerbation of asthma symptoms and other respiratory problems. Other studies are inconclusive or deny this correlation. This makes the association between PAR and airway hypersensitivity very controversial and still under debate. OBJECTIVE: This work investigated if chronic treatment with PAR in rats could directly affect the contraction and relaxation for different stimulus in isolated airways. METHODS: Rats were treated for 2 weeks with PAR (400 mg/Kg, v.o.). The blood was collected for biochemical analysis (alanine aminotransferase (ALT), aspartate aminotransferase (AST), TBARs reaction and glutathione) and isolated tracheal rings were prepared in organ bath to measure isometric tone after contractile and relaxant stimulus. RESULTS: Hepatic enzymes (ALT, AST) and lipid peroxidation were increased after PAR-treatment, while glutathione was decreased. Rats do not present any alteration in airway myocytes responsiveness, either to contractile or relaxant stimulus (i.e. cholinergic agonist, membrane depolarization, Ca2+ influx across sarcolemma, internal Ca2+ release from sarcoplasmic reticulum, Ca2+ channel blocking, ß-agonist and NOmediating relaxation). CONCLUSION: Despite increased oxidative stress and reduced antioxidant defense, chronic treatment with PAR does not induce airway hypersensitivity or risk of asthma in rats.
Asunto(s)
Acetaminofén/toxicidad , Asma/inducido químicamente , Alanina Transaminasa/sangre , Animales , Aspartato Aminotransferasas/sangre , Asma/metabolismo , Carbacol/farmacología , Glutatión/sangre , Peroxidación de Lípido/efectos de los fármacos , Masculino , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Ratas , Ratas Wistar , Tráquea/efectos de los fármacosRESUMEN
Channelopsins and photo-regulated ion channels make it possible to use light to control electrical activity of cells. This powerful approach has lead to a veritable explosion of applications, though it is limited to changing membrane voltage of the target cells. An enormous potential could be tapped if similar opto-genetic techniques could be extended to the control of chemical signaling pathways. Photopigments from invertebrate photoreceptors are an obvious choice-as they do not bleach upon illumination -however, their functional expression has been problematic. We exploited an unusual opsin, pScop2, recently identified in ciliary photoreceptors of scallop. Phylogenetically, it is closer to vertebrate opsins, and offers the advantage of being a bi-stable photopigment. We inserted its coding sequence and a fluorescent protein reporter into plasmid vectors and demonstrated heterologous expression in various mammalian cell lines. HEK 293 cells were selected as a heterologous system for functional analysis, because wild type cells displayed the largest currents in response to the G-protein activator, GTP-γ-S. A line of HEK cells stably transfected with pScop2 was generated; after reconstitution of the photopigment with retinal, light responses were obtained in some cells, albeit of modest amplitude. In native photoreceptors pScop2 couples to Go; HEK cells express poorly this G-protein, but have a prominent Gq/PLC pathway linked to internal Ca mobilization. To enhance pScop2 competence to tap into this pathway, we swapped its third intracellular loop-important to confer specificity of interaction between 7TMDRs and G-proteins-with that of a Gq-linked opsin which we cloned from microvillar photoreceptors present in the same retina. The chimeric construct was evaluated by a Ca fluorescence assay, and was shown to mediate a robust mobilization of internal calcium in response to illumination. The results project pScop2 as a potentially powerful optogenetic tool to control signaling pathways.
Asunto(s)
Luz , Opsinas/metabolismo , Transducción de Señal/efectos de la radiación , Secuencia de Aminoácidos , Animales , Calcio/metabolismo , Carbacol/farmacología , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/química , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Células HEK293 , Humanos , Potenciales de la Membrana , Opsinas/clasificación , Opsinas/genética , Técnicas de Placa-Clamp , Pectinidae/metabolismo , Filogenia , Dominios Proteicos , Retina/metabolismo , Retina/patología , Alineación de Secuencia , Transducción de Señal/efectos de los fármacos , Fosfolipasas de Tipo C/metabolismoRESUMEN
In the right atrium (RA), adenosine and acetylcholine inhibit the pacemaker function of the sinoatrial node and induce cardiac arrest. Pre-incubation of receptor antagonists is known to inhibit the cardiac arrest induced by these agonists; however, the effect of antagonist administration after established cardiac arrest has not been described. Therefore, we assessed whether specific receptor antagonists could revert cardiac arrest induced by adenosine and muscarinic receptors activation. RA isolated from adults Wistar rats were mounted in an organ bath containing Krebs solution. Cardiac arrest was induced by adenosine or ATP (1mM), the A1 adenosine receptor agonist CPA (0.1-1µM), and muscarinic receptor agonists, carbachol (0.3-1µM) and acetylcholine (1mM). After establishing the cardiac arrest, the A1 adenosine receptor antagonist DPCPX (0.3-30µM), the muscarinic receptor antagonist atropine (10nM to 100µM) or the phosphodiesterase inhibitor IBMX (10-300µM) were incubated in order to check for the return of spontaneous contractions. DPCPX reversed the cardiac arrest induced by adenosine, ATP and CPA. In addition, atropine reversed the cardiac arrest induced by carbachol. Unexpectedly, DPCPX also reversed the cardiac arrest induced by carbachol. Similarly to DPCPX, the phosphodiesterase inhibitor IBMX reversed the cardiac arrest induced by adenosine, CPA and carbachol. The antagonism of adenosine and acetylcholine receptors activation, as well as phosphodiesterase inhibition, are able to revert cardiac arrest. DPCPX restore spontaneous contractions via the selective antagonism of A1 adenosine receptor and through a secondary mechanism likely related to phosphodiesterase inhibition.
Asunto(s)
Agonistas del Receptor de Adenosina A1/farmacología , Paro Cardíaco/inducido químicamente , Paro Cardíaco/tratamiento farmacológico , Agonistas Muscarínicos/farmacología , Receptor de Adenosina A1/metabolismo , Receptores Muscarínicos/metabolismo , Xantinas/farmacología , Animales , Carbacol/farmacología , Masculino , Ratas , Ratas Wistar , Xantinas/uso terapéuticoRESUMEN
NEW FINDINGS: What is the central question of this study? Acute acidosis that results from short-term exercise is involved in delayed gastric emptying in rats and the lower responsiveness of gastric fundus strips to carbachol. Does extracellular acidosis decrease responsiveness to carbachol in tissues of sedentary rats? How? What is the main finding and its importance? Extracellular acidosis inhibits cholinergic signalling in the rat gastric fundus by selectively influencing the Gq/11 protein signalling pathway. Acute acidosis that results from short-term exercise delays gastric emptying in rats and decreases the responsiveness to carbachol in gastric fundus strips. The regulation of cytosolic Ca2+ concentrations appears to be a mechanism of action of acidosis. The present study investigated the way in which acidosis interferes with gastric smooth muscle contractions. Rat gastric fundus isolated strips at pH 6.0 presented a lower magnitude of carbachol-induced contractions compared with preparations at pH 7.4. This lower magnitude was absent in carbachol-stimulated duodenum and KCl-stimulated gastric fundus strips. In Ca2+ -free conditions, repeated contractions that were induced by carbachol progressively decreased, with no influence of extracellular pH. In fundus strips, CaCl2 -induced contractions were lower at pH 6.0 than at pH 7.4 but only when stimulated in the combined presence of carbachol and verapamil. In contrast, verapamil-sensitive contractions that were induced by CaCl2 in the presence of KCl did not change with pH acidification. In Ca2+ store-depleted preparations that were treated with thapsigargin, the contractions that were induced by extracellular Ca2+ restoration were smaller at pH 6.0 than at pH 7.4, but relaxation that was induced by SKF-96365 (an inhibitor of store-operated Ca2+ entry) was unaltered by extracellular acidification. At pH 6.0, the phospholipase C inhibitor U-73122 relaxed carbachol-induced contractions less than at pH 7.4, and this phenomenon was absent in tissue that was treated with the RhoA kinase blocker Y-27632. Thus, extracellular acidosis inhibited pharmacomechanical coupling in gastric fundus by selectively inhibiting the Gq/11 protein signalling pathway, whereas electromechanical coupling remained functionally preserved.
Asunto(s)
Acidosis/metabolismo , Señalización del Calcio/efectos de los fármacos , Carbacol/farmacología , Agonistas Colinérgicos/farmacología , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Vaciamiento Gástrico/efectos de los fármacos , Fundus Gástrico/efectos de los fármacos , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Fundus Gástrico/metabolismo , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Masculino , Músculo Liso/metabolismo , Ratas WistarRESUMEN
The anterior cingulate cortex (ACC) is crucial in the modulation of the sensory, affective and cognitive aspects of nociceptive processing. Also, it participates in the planning and execution of behavioral responses evoked by nociceptive stimuli via descending projections to the brainstem. In laboratory animals nociceptive experimental tests evaluate behavioral responses that preferentially express the sensory-discriminative or affective-motivational component of pain. The objective of this study was to investigate the participation of opioid and cholinergic neurotransmission in the ACC on different nociceptive responses in guinea pigs. We used nociceptive tests of formalin and vocalization evoked by peripheral noxious stimuli (electric shock) to evaluate the behavioral expression of the sensory-discriminative and affective motivational components, respectively. We verified that the microinjection of morphine (4.4nmol) in the ACC of guinea pigs promotes antinociception in the two experimental tests investigated. This effect is blocked by prior microinjection of naloxone (2.7nmol). On the other hand, the microinjection of carbachol (2.7nmol) in the ACC induces antinociception only in the vocalization test. This effect was prevented by prior microinjection of atropine (0.7nmol) and naloxone (2.7nmol). In fact, the blockade of µ-opioids receptors with naloxone in ACC prevented the antinociceptive effect of carbachol in the vocalization test. Accordingly, we suggest that the antinociception promoted by carbachol was mediated by the activation of muscarinic receptors on local ACC opioid interneurons. The release of endogenous opioids seems to inhibited the expression of the behavioral response of vocalization. Therefore, we verified that the antinociceptive effect of morphine microinjection in ACC is broader and more robust than that promoted by carbachol.
Asunto(s)
Giro del Cíngulo/metabolismo , Nociceptores/fisiología , Receptores Opioides/metabolismo , Vocalización Animal/fisiología , Acetilcolina/farmacología , Analgésicos Opioides/farmacología , Animales , Atropina/farmacología , Carbacol/metabolismo , Carbacol/farmacología , Colinérgicos/farmacología , Cobayas , Giro del Cíngulo/efectos de los fármacos , Masculino , Microinyecciones , Morfina/metabolismo , Morfina/farmacología , Muscimol/farmacología , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Nociceptores/efectos de los fármacos , Péptidos Opioides/metabolismo , Dolor/tratamiento farmacológico , Dolor/metabolismo , Dolor/prevención & control , Transmisión Sináptica/efectos de los fármacos , Vocalización Animal/efectos de los fármacosRESUMEN
AIMS: Androgen deficiency has been implicated in urological complications of postmenopausal women. This study examined the effects of testosterone replacements on the lower urinary tract dysfunction in 4-month old ovariectomized (OVX) rats. MAIN METHODS: Sprague-Dawley female rats were OVX bilaterally. Three months later, rats received single intramuscular injections of testosterone undecanoate. Cystometric study, and bladder and urethra smooth muscle reactivities were evaluated. KEY FINDINGS: Ovariectomy reduced by 65% (p<0.05) the serum testosterone levels. Testosterone replacement at 5mg/kg restored serum hormone levels to baseline, whereas 10mg/kg produced 14-fold higher testosterone levels. OVX rats exhibited significant increases of body weight, perigonadal fat and blood pressure, and reduced uterus weight, but none of these parameters were changed by testosterone replacements. OVX rats exhibited micturition dysfunction characterized by increases of basal pressure, threshold pressure, voiding frequency and post-voiding pressure. In addition, the bladder contractions induced by electrical-field stimulation (EFS) and carbachol were significantly reduced, whereas angiotensin II-induced urethral contractions were significantly increased in OVX rats. Testosterone replacement at 10mg/kg (but not at 5mg/kg) dose fully normalized the in vivo micturition dysfunction, as well as the in vitro bladder and urethral alterations. Testosterone (10mg/kg) also significantly potentiated the bladder relaxations induced by the ß3-adrenoceptor agonist mirabegron. The protective effects of testosterone were not modified by concomitant treatment with the aromatase inhibitor letrozole (2.5mg/kg, 4weeks). SIGNIFICANCE: The improvement of micturition dysfunction by testosterone replacement suggests that androgen therapy might be of therapeutic benefit for urological complications associated with post-menopause.
Asunto(s)
Andrógenos/administración & dosificación , Músculo Liso/efectos de los fármacos , Posmenopausia , Testosterona/análogos & derivados , Trastornos Urinarios/tratamiento farmacológico , Acetanilidas/farmacología , Andrógenos/farmacología , Angiotensina II/farmacología , Animales , Carbacol/farmacología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Inyecciones Intramusculares , Letrozol , Músculo Liso/metabolismo , Nitrilos/farmacología , Ovariectomía , Ratas , Ratas Sprague-Dawley , Testosterona/administración & dosificación , Testosterona/farmacología , Tiazoles/farmacología , Triazoles/farmacología , Uretra/efectos de los fármacos , Uretra/metabolismo , Trastornos Urinarios/etiologíaRESUMEN
Testosterone (TES), other androgens and female sex steroids induce non-genomic rapid relaxing effects in airway smooth muscle (ASM). In guinea pig ASM, basal tension was relaxed by dehydroepiandrosterone (DHEA) and TES; 17ß-estradiol (E2) had a small effect. Blockers of L-type voltage dependent Ca2+ channel (L-VDCC, D-600) and store operated Ca2+ channel (SOC, 2-APB) also relaxed the basal tone. In tracheal myocytes, DHEA and TES diminished intracellular basal Ca2+ concentrations (b[Ca2+]i) as D-600+2-APB but to a higher extend. TES after D-600+2APB or Pyr3, a blocker of canonical transient receptor potential 3 (TRPC3), further decreased b[Ca2+]i rendering this response equal to TES alone. With indomethacin, the b[Ca2+]i decrease induced by the blockade of L-VDCC and TRPC3 was not changed by the addition of TES. PGE2 or forskolin addition after D600+2-APB, decreased b[Ca2+]i resembling TES response. An adenylate cyclase inhibitor followed by D-600+2-APB lowered b[Ca2+]i, TES showed no further effect. Carbachol-induced [Ca2+]i increment was reduced by TES or DHEA. 17ß-estradiol diminished KCl-induced contraction and, in tracheal myocytes, the voltage-dependent inward Ca2+ current. CONCLUSION: DHEA and TES diminish ASM tone and b[Ca2+]i by blocking L-VDCC and probably a constitutively active TRPC3, and by PGE2 synthesis. E2 lowers ASM basal tone by blocking only L-VDCC.
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Canales de Calcio Tipo L/metabolismo , Calcio/metabolismo , Hormonas Esteroides Gonadales/farmacología , Espacio Intracelular/metabolismo , Músculo Liso/fisiología , Tráquea/fisiología , Animales , Compuestos de Boro/farmacología , Carbacol/farmacología , AMP Cíclico/metabolismo , Deshidroepiandrosterona/farmacología , Estradiol/farmacología , Galopamilo/farmacología , Cobayas , Masculino , Células Musculares/efectos de los fármacos , Células Musculares/metabolismo , Músculo Liso/efectos de los fármacos , Prostaglandinas/metabolismo , Canales Catiónicos TRPC/metabolismo , Testosterona/farmacologíaRESUMEN
AIMS: To evaluate the effects of the beta-3 adrenoceptor agonist, mirabegron in a mouse model of detrusor overactivity induced by obesity. METHODS: C57BL/6 male mice were fed with standard chow or high-fat diet for 12 weeks. Lean and obese mice were treated orally with mirabegron (10 mg/kg/day) from the last 2 weeks of diet. Cystometric evaluations, functional assays, protein expression for phosphodiesterase type 4 (PDE4), and cyclic adenosine monophosphate (cAMP) measurement were carried out. RESULTS: In obese mice the body weight, epididymal fat mass, fasting glucose, and low-density lipoprotein (LDL) levels were higher (P < 0.001) than in the lean mice. A reduction of 34% and 54% and an increase of 35% in the epididimal fat, LDL, and HDL levels (P < 0.05), respectively, were observed in the obese group treated with mirabegron, whereas no changes were seen in the lipid profile from lean mice. Obese group showed irregular micturition pattern, characterized by significant increases in frequency and non-void contractions. Carbachol, potassium chloride, and electrical-field stimulation induced detrusor smooth muscle (DSM) contractions, which were greater in bladders from obese mice than from lean mice. Two-week treatment with mirabegron restored all the contractile response alterations in the DSM. Basal intracellular levels of cAMP were reduced (68%), whereas PDE4 protein expression was increased (54%) in bladder from obese mice. Mirabegron restored the cAMP levels in obese bladder, without changing the PDE4 expression. CONCLUSION: Mirabegron was able to completely restore the urinary alterations seen in the bladder from obese mice.
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Acetanilidas/uso terapéutico , Agonistas de Receptores Adrenérgicos beta 3/uso terapéutico , AMP Cíclico/metabolismo , Músculo Liso/efectos de los fármacos , Obesidad/fisiopatología , Tiazoles/uso terapéutico , Vejiga Urinaria Hiperactiva/tratamiento farmacológico , Acetanilidas/farmacología , Agonistas de Receptores Adrenérgicos beta 3/farmacología , Animales , Peso Corporal/efectos de los fármacos , Carbacol/farmacología , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Contracción Muscular/efectos de los fármacos , Músculo Liso/metabolismo , Músculo Liso/fisiopatología , Obesidad/metabolismo , Tiazoles/farmacología , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/metabolismo , Vejiga Urinaria/fisiopatología , Vejiga Urinaria Hiperactiva/metabolismo , Vejiga Urinaria Hiperactiva/fisiopatología , Micción/efectos de los fármacosRESUMEN
Herein, we investigated whether subdiaphragmatic vagotomy has benefits on obesity, body glucose homeostasis, and insulin secretion in cafeteria (CAF)-obese rats. Wistar rats were fed a standard or CAF diet for 12 weeks. Subsequently, CAF rats were randomly submitted to truncal vagotomy (CAF Vag) or sham operation (CAF Sham). CAF Sham rats were hyperphagic, obese, and presented metabolic disturbances, including hyperinsulinemia, glucose intolerance, insulin resistance, hyperglycemia, and hypertriglyceridemia. Twelve weeks after vagotomy, CAF Vag rats presented reductions in body weight and perigonadal fat stores. Vagotomy did not modify glucose tolerance but normalized fed glycemia, insulinemia, and insulin sensitivity. Isolated islets from CAF Sham rats secreted more insulin in response to the cholinergic agent, carbachol, and when intracellular cyclic adenine monophosphate (cAMP) is enhanced by forskolin or 3-isobutyl-1-methylxanthine. Vagotomy decreased glucose-induced insulin release due to a reduction in the cholinergic action on ß-cells. This effect also normalized islet secretion in response to cAMP. Therefore, vagotomy in rats fed on a CAF-style diet effectively decreases adiposity and restores insulin sensitivity. These effects were mainly associated with the lack of cholinergic action on the endocrine pancreas, which decreases insulinemia and may gradually reduce fat storage and improve insulin sensitivity.
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Hiperglucemia/cirugía , Hiperinsulinismo/cirugía , Hipertrigliceridemia/cirugía , Obesidad/cirugía , Vagotomía , Nervio Vago/cirugía , 1-Metil-3-Isobutilxantina/farmacología , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Carbacol/farmacología , Colforsina/farmacología , AMP Cíclico/metabolismo , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Glucosa/metabolismo , Glucosa/farmacología , Hiperglucemia/etiología , Hiperglucemia/metabolismo , Hiperglucemia/patología , Hiperinsulinismo/etiología , Hiperinsulinismo/metabolismo , Hiperinsulinismo/patología , Hipertrigliceridemia/etiología , Hipertrigliceridemia/metabolismo , Hipertrigliceridemia/patología , Insulina/metabolismo , Resistencia a la Insulina , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Masculino , Obesidad/etiología , Obesidad/metabolismo , Obesidad/patología , Ratas , Ratas Wistar , Técnicas de Cultivo de Tejidos , Nervio Vago/metabolismoRESUMEN
Activators of soluble guanylyl cyclase (sGC) interact directly with its prosthetic heme group, enhancing the enzyme responsiveness in pathological conditions. This study aimed to evaluate the effects of the sGC activator BAY 58-2667 on voiding dysfunction, protein expressions of α1 and ß1 sGC subunits and cGMP levels in the bladder tissues after cyclophosphamide (CYP) exposure. Female C57BL/6 mice (20-25 g) were injected with CYP (300 mg/kg ip) to induce cystitis. Mice were pretreated or not with BAY 58-2667 (1 mg/kg, gavage), given 1 h before CYP injection. The micturition patterns and in vitro bladder contractions were evaluated at 24 h. In freely moving mice, the CYP injection produced reduced the micturition volume and increased the number of urine spots. Cystometric recordings in CYP-injected mice revealed significant increases in basal pressure, voiding frequency, and nonvoiding contractions (NVCs), along with decreases in bladder capacity, intercontraction interval, and compliance. BAY 58-2667 significantly prevented the micturition alterations observed in both freely moving mice and cystometry and normalized the reduced in vitro carbachol-induced contractions in the CYP group. Reduced protein expressions of α1 and ß1 sGC subunits and of cGMP levels were observed in the CYP group, all of which were prevented by BAY 58-2667. CYP exposure significantly increased reactive-oxygen species (ROS) generation in both detrusor and urothelium, and this was normalized by BAY 58-2667. The increased myeloperoxidase and cyclooxygenase-2 activities in the bladders of the CYP group remained unchanged by BAY 58-2667. Activators of sGC may constitute a novel and promising therapeutic approach for management of interstitial cystitis.
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Benzoatos/uso terapéutico , Cistitis/tratamiento farmacológico , Cistitis/fisiopatología , Activadores de Enzimas/uso terapéutico , Guanilil Ciclasa Soluble/efectos de los fármacos , Vejiga Urinaria/fisiopatología , Alquilantes , Animales , Carbacol/farmacología , AMP Cíclico/metabolismo , Ciclooxigenasa 2/metabolismo , Ciclofosfamida , Cistitis/inducido químicamente , Edema/inducido químicamente , Edema/fisiopatología , Edema/prevención & control , Ratones , Ratones Endogámicos C57BL , Antagonistas Muscarínicos/farmacología , Peroxidasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Vejiga Urinaria/metabolismoRESUMEN
α-Terpineol is a monoterpene with smooth muscle relaxant properties. In this study, its effects on the gastric emptying rate of awake rats were evaluated with emphasis on the mode by which it induces gastrointestinal actions. Administered by gavage, α-terpineol (50 mg/kg) delayed gastric emptying of a liquid test meal at 10 min postprandial. Hexamethonium or guanethidine did not interfere with the retarding effect induced by α-terpineol, but atropine and L-NG-nitroarginine methyl ester abolished it. In vagotomized rats, α-terpineol did not delay gastric emptying. In isolated strips of gastric fundus, concentration-effect curves in response to carbamylcholine were higher in magnitude after treatment with the monoterpene. α-Terpineol (1 to 2000 µM) relaxed sustained contractions induced by carbamylcholine or a high K+ concentration in a concentration-dependent manner. This relaxing effect was not affected by the presence of L-NG-nitroarginine methyl ester, 1 H-[1,â2,â4]oxadiazolo[4,3-a]quinoxalin-1-one, tetraethylammonium, or atropine. Smooth muscle contractions induced by electrical field stimulation were inhibited by α-terpineol. In conclusion, α-terpineol induced gastric retention in awake rats through mechanisms that depended on intact vagal innervation to the stomach, which involved cholinergic/nitrergic signalling. Such a retarding effect induced by α-terpineol appears not to result from a direct action of the monoterpene on gastric smooth muscle cells.
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Ciclohexenos/farmacología , Vaciamiento Gástrico/efectos de los fármacos , Fundus Gástrico/efectos de los fármacos , Monoterpenos/farmacología , Nervio Vago/efectos de los fármacos , Animales , Atropina/farmacología , Carbacol/farmacología , Monoterpenos Ciclohexánicos , Ciclohexenos/administración & dosificación , Relación Dosis-Respuesta a Droga , Vaciamiento Gástrico/fisiología , Guanetidina/farmacología , Masculino , Monoterpenos/administración & dosificación , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico/metabolismo , Técnicas de Cultivo de Órganos , Potasio/farmacología , Ratas Wistar , Simpaticolíticos/farmacología , Vagotomía , Nervio Vago/metabolismo , Nervio Vago/cirugíaRESUMEN
BACKGROUND: It is actually known that acetylcholine works as a signaling molecule in non-neuronal cells and tissues, in addition to its neuronal function as neurotransmitter. It can act on two types of receptors nicotinic and muscarinic receptors (mAChRs). The latter belong to the G protein coupled receptor family and there are five subtypes genetically cloned. Their activation triggers classical and non-classical intracellular signals that could be linked to the proliferation of normal and/or transformed cells. The M3 subtype was identified in different types of tumors and its stimulation with agonists triggers cell proliferation, migration, invasion and metastasis. RESULTS: Our laboratory has extensively investigated the expression and function of mAChRs in breast tumors from animal and human origins. We found a profuse expression of mAChRs in breast tumors, but opposite to this, an absence of these receptors in normal breast cells and tissues. The stimulation of mAChRs with the cholinergic agonist carbachol for 20 h increased tumor cell death. Moreover, the combination of subthreshold concentrations of the agonist with paclitaxel potentiates cell death. The usage of low dose chemotherapy with short drug free intervals was named metronomic therapy and it has emerged as a novel regimen for cancer treatment with very low incidence of side effects. CONCLUSION: Our work and that of others indicate that mAChRs that are over-expressed in different types of tumor cells could be a useful target for metronomic therapy in cancer treatment.
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Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Carbacol/farmacología , Agonistas Colinérgicos/farmacología , Paclitaxel/farmacología , Receptores Muscarínicos/metabolismo , Administración Metronómica , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Carbacol/administración & dosificación , Agonistas Colinérgicos/administración & dosificación , Femenino , Humanos , Paclitaxel/administración & dosificación , Receptores Muscarínicos/genéticaRESUMEN
The central control of the micturition is dependent on cortical areas and other ascending and descending pathways in the brain stem. The descendent pathways from the pons to the urinary bladder (UB) can be direct or indirect through medullary neurons (MN). Chemical stimulation with l-glutamate of MN known for their involvement in cardiovascular regulation evokes changes in pelvic nerves activities, which innervate the urinary bladder. Different neurotransmitters have been found in medullary areas; nevertheless, their involvement in UB control is few understood. We focused to investigate if cholinergic activation of neurons in the medulla oblongata changes the urinary bladder activity. Carbachol (cholinergic agonist) or atropine (cholinergic antagonist) was injected into the 4thV in anesthetized female Wistar rats and the intravesical pressure (IP), mean arterial pressure (MAP), heart rate (HR) and renal conductance (RC) were recorded for 30 min. Carbachol injection into the 4thV increased IP with peak response at 30 min after carbachol and yielded no changes in MAP, HR and RC. Atropine injection into the 4thV decreased IP and elicited no changes in MAP, HR and RC. Plasma vasopressin levels evaluated by ELISA kit assay increased after carbachol into the 4th V. Intravenous blockade of V1 receptors prior to carbachol into the 4thV abolished the increase in IP evoked by carbachol. Therefore, our findings suggest that cholinergic activation of neurons in the medulla oblongata by carbachol injections into the 4thV increases IP due to plasma vasopressin release, which acts in V1 receptors in the UB.
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Acetilcolina/metabolismo , Bulbo Raquídeo/citología , Neuronas/citología , Neuronas/efectos de los fármacos , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/fisiología , Vasopresinas/sangre , Animales , Antagonistas de los Receptores de Hormonas Antidiuréticas/farmacología , Arginina Vasopresina/análogos & derivados , Arginina Vasopresina/farmacología , Presión Arterial/efectos de los fármacos , Atropina/farmacología , Carbacol/farmacología , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Bulbo Raquídeo/fisiología , Oxitocina/sangre , Ratas , Ratas Wistar , Receptores de Vasopresinas/metabolismo , Vasopresinas/metabolismoRESUMEN
Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the gamma band (30-45 Hz) of the electroencephalogram (EEG) have been involved in these cognitive functions. In previous studies, we analysed the extent of functional connectivity between cortical areas employing the 'mean squared coherence' analysis of the EEG gamma band. We demonstrated that gamma coherence is maximal during alert wakefulness and is almost absent during rapid eye movement (REM) sleep. The nucleus pontis oralis (NPO) is critical for REM sleep generation. The NPO is considered to exert executive control over the initiation and maintenance of REM sleep. In the cat, depending on the previous state of the animal, a single microinjection of carbachol (a cholinergic agonist) into the NPO can produce either REM sleep [REM sleep induced by carbachol (REMc)] or a waking state with muscle atonia, i.e. cataplexy [cataplexy induced by carbachol (CA)]. In the present study, in cats that were implanted with electrodes in different cortical areas to record polysomnographic activity, we compared the degree of gamma (30-45 Hz) coherence during REMc, CA and naturally-occurring behavioural states. Gamma coherence was maximal during CA and alert wakefulness. In contrast, gamma coherence was almost absent during REMc as in naturally-occurring REM sleep. We conclude that, in spite of the presence of somatic muscle paralysis, there are remarkable differences in cortical activity between REMc and CA, which confirm that EEG gamma (≈40 Hz) coherence is a trait that differentiates wakefulness from REM sleep.