RESUMO
PURPOSE: To perform a quantitative assessment of different types of pelvic ureter tissues with chronic dilation in adults, using stereological methods. METHODS: We analyzed fragments of dilated pelvic ureters obtained from 6 patients aged between 35 and 67 years (mean, 46 years) who underwent ureteral reimplantation surgery for different reasons. The obstruction duration ranged from 27 to 180 days (mean, 93 days). The control group included fragments of normal pelvic ureters obtained during nephrectomy in 7 kidney transplant donors (age: range, 25-51 years; mean, 36 years). The volumetric density of collagen in the ureter, elastic fibers, and smooth muscle fibers was assessed. RESULTS: The volumetric density (Vv) of collagen showed no significant difference between the two groups (control: 45.3 ± 6.1; dilated: 40.8 ± 6.9; P = 0.23). A statistically significant increase in Vv of elastic fibers was observed in the dilated ureters (control: 18.4 ± 1.2; dilated: 24.6 ± 5.4; P = 0.03). A statistically significant increase in the Vv of smooth muscle fibers was observed in the dilated ureter (control: 42.0 ± 6.0; dilated: 56.2 ± 6.1; P = 0.001). CONCLUSION: The chronically dilated pelvic ureters had significantly more elastin and smooth muscle contents than the controls.
Assuntos
Colágeno/ultraestrutura , Ureter/patologia , Adulto , Idoso , Dilatação Patológica/patologia , Tecido Elástico/ultraestrutura , Feminino , Humanos , Imuno-Histoquímica , Masculino , Microscopia de Polarização , Pessoa de Meia-Idade , Músculo Liso/ultraestruturaRESUMO
PURPOSE: To perform a quantitative assessment of different types of pelvic ureter tissues with chronic dilation in adults, using stereological methods. METHODS: We analyzed fragments of dilated pelvic ureters obtained from 6 patients aged between 35 and 67 years (mean, 46 years) who underwent ureteral reimplantation surgery for different reasons. The obstruction duration ranged from 27 to 180 days (mean, 93 days). The control group included fragments of normal pelvic ureters obtained during nephrectomy in 7 kidney transplant donors (age: range, 25-51 years; mean, 36 years). The volumetric density of collagen in the ureter, elastic fibers, and smooth muscle fibers was assessed. RESULTS: The volumetric density (Vv) of collagen showed no significant difference between the two groups (control: 45.3 ± 6.1; dilated: 40.8 ± 6.9; P = 0.23). A statistically significant increase in Vv of elastic fibers was observed in the dilated ureters (control: 18.4 ± 1.2; dilated: 24.6 ± 5.4; P = 0.03). A statistically significant increase in the Vv of smooth muscle fibers was observed in the dilated ureter (control: 42.0 ± 6.0; dilated: 56.2 ± 6.1; P = 0.001). CONCLUSION: The chronically dilated pelvic ureters had significantly more elastin and smooth muscle contents than the controls. .
Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Colágeno/ultraestrutura , Ureter/patologia , Dilatação Patológica/patologia , Tecido Elástico/ultraestrutura , Imuno-Histoquímica , Microscopia de Polarização , Músculo Liso/ultraestruturaRESUMO
BACKGROUND: Cimetidine, histamine H2 receptors antagonist, has caused adverse effects on the male hormones and reproductive tract due to its antiandrogenic effect. In the testes, peritubular myoid cells and muscle vascular cells death has been associated to seminiferous tubules and testicular microvascularization damages, respectively. Either androgen or histamine H2 receptors have been detected in the mucosa and smooth muscular layer of vas deferens. Thus, the effect of cimetidine on this androgen and histamine-dependent muscular duct was morphologically evaluated. METHODS: The animals from cimetidine group (CMTG; n=5) received intraperitoneal injections of 100 mg/kg b.w. of cimetidine for 50 days; the control group (CG) received saline solution. The distal portions of vas deferens were fixed in formaldehyde and embedded in paraffin. Masson´s trichrome-stained sections were subjected to morphological and the following morphometrical analyzes: epithelial perimeter and area of the smooth muscular layer. TUNEL (Terminal deoxynucleotidyl-transferase mediated dUTP Nick End Labeling) method, NF-kB (nuclear factor kappa B) and AR (androgen receptors) immunohistochemical detection were also carried out. The birefringent collagen of the muscular layer was quantified in picrosirius red-stained sections under polarized light. The muscular layer was also evaluated under Transmission Electron Microscopy (TEM). RESULTS: In CMTG, the mucosa of vas deferens was intensely folded; the epithelial cells showed numerous pyknotic nuclei and the epithelial perimeter and the area of the muscular layer decreased significantly. Numerous TUNEL-labeled nuclei were found either in the epithelial cells, mainly basal cells, or in the smooth muscle cells which also showed typical features of apoptosis under TEM. While an enhanced NF-kB immunoexpression was found in the cytoplasm of muscle cells, a weak AR immunolabeling was detected in these cells. In CMTG, no significant difference was observed in the birefringent collagen content of the muscular layer in comparison to CG. CONCLUSIONS: Cimetidine induces significant damages in the epithelium; a possible antiandrogenic effect on the basal cells turnover should be considered. The cimetidine-induced muscle cells apoptosis confirms the susceptibility of these cells to this drug. The parallelism between enhanced cytoplasmic NF-kB immunolabeling in the damaged muscular tissue and muscle cell apoptosis suggests that this drug may avoid the translocation of NF-kB to the nucleus and interfere in the control of NF-kB-mediated smooth muscle cell apoptosis. The decreased immunoexpression of ARs verified in the damaged muscular tissue reinforces this possibility.
Assuntos
Apoptose/efeitos dos fármacos , Cimetidina/farmacologia , Músculo Liso/efeitos dos fármacos , NF-kappa B/metabolismo , Receptores Androgênicos/metabolismo , Ducto Deferente/efeitos dos fármacos , Animais , Colágeno/metabolismo , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Epitélio/patologia , Antagonistas dos Receptores H2 da Histamina/farmacologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Masculino , Microscopia Eletrônica de Transmissão , Músculo Liso/metabolismo , Músculo Liso/ultraestrutura , Ratos , Ducto Deferente/metabolismo , Ducto Deferente/patologiaRESUMO
It is known that the development of diabetic complications in human pregnancy is directly related to the severity and the duration of this pathology. In this study, we developed a model of long-term type 1 diabetes to investigate its effects on the cytoarchitecture, extracellular matrix and cell proliferation during the first adaptation phase of the myometrium for pregnancy. A single dose of alloxan was used to induce diabetes in mice prior to pregnancy. To identify the temporal effects of diabetes the mice were divided into two groups: Group D1 (females that became pregnant 90-100 days after alloxan); Group D2 (females that became pregnant 100-110 days after alloxan). Uterine samples were collected after 168 h of pregnancy and processed for light and electron microscopy. In both groups the histomorphometric evaluation showed that diabetes promoted narrowing of the myometrial muscle layers which was correlated with decreased cell proliferation demonstrated by PCNA immunodetection. In D1, diabetes increased the distance between muscle layers and promoted oedema. Contrarily, in D2 the distance between muscle layers decreased and, instead of oedema, there was a markedly deposition of collagen in the myometrium. Ultrastructural analysis showed that diabetes affects the organization of the smooth muscle cells and their myofilaments. Consistently, the immunoreaction for smooth muscle α-actin revealed clear disorganization of the contractile apparatus in both diabetic groups. In conclusion, the present model demonstrated that long-term diabetes promotes significant alterations in the myometrium in a time-sensitive manner. Together, these alterations indicate that diabetes impairs the first phenotypic adaptation phase of the pregnant myometrium.
Assuntos
Diabetes Mellitus Experimental/patologia , Miométrio/patologia , Complicações na Gravidez/patologia , Adaptação Fisiológica/fisiologia , Animais , Divisão Celular/fisiologia , Diabetes Mellitus Experimental/fisiopatologia , Modelos Animais de Doenças , Feminino , Idade Gestacional , Humanos , Camundongos , Microscopia Eletrônica , Músculo Liso/patologia , Músculo Liso/fisiologia , Músculo Liso/ultraestrutura , Miométrio/fisiologia , Miométrio/ultraestrutura , Gravidez , Complicações na Gravidez/fisiopatologia , Fatores de Tempo , Contração Uterina/fisiologiaRESUMO
Differently graded areas of human prostate adenocarcinoma were examined after Masson's trichrome staining or immunohistochemistry for smooth muscle alpha-actin, type IV collagen and laminin. In addition, the ultrastructure of the prostatic smooth muscle cells (SMC) during glandular proliferation and epithelial invasion in selected tumors was studied. The SMC formed a thick layer below the epithelial structures in unaffected areas and were closely associated with each other in homotypic interactions. As the tumor grade increased, the SMC gradually lost interactions with each other and became atrophic. With the growth of the epithelial compartment, the SMC initially segregated to the tumor periphery and the intercellular spaces increased. In high grade tumors, the epithelial cancer cells invaded the spaces between the SMC. Immunohistochemical analysis of the basal membrane revealed increased disruption of the usually thick basal membrane, which became thinner and faintly stained with each of the antibodies used. We conclude that most SMC become atrophic following epithelial invasion in human tumors and that degradation of the basal membrane is an important factor in this process. At the ultrastructural level, different SMC phenotypes occur in prostatic tissues during epithelial invasion. Interconversion between these phenotypes is suggested and a probable relationship among them is proposed.
Assuntos
Músculo Liso/citologia , Músculo Liso/patologia , Próstata/fisiologia , Neoplasias da Próstata/patologia , Actinas/análise , Humanos , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Músculo Liso/ultraestrutura , Próstata/patologia , Próstata/ultraestrutura , Neoplasias da Próstata/ultraestrutura , Valores de ReferênciaRESUMO
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.
Assuntos
Íleo/ultraestrutura , Isquemia/patologia , Oclusão Vascular Mesentérica/complicações , Músculo Liso/ultraestrutura , Plexo Mientérico/ultraestrutura , Neurônios/ultraestrutura , Animais , Constrição , Modelos Animais de Doenças , Cobaias , Íleo/irrigação sanguínea , Íleo/inervação , Íleo/fisiopatologia , Isquemia/etiologia , Isquemia/fisiopatologia , Masculino , Artérias Mesentéricas/cirurgia , Oclusão Vascular Mesentérica/patologia , Oclusão Vascular Mesentérica/fisiopatologia , Contração Muscular , Músculo Liso/irrigação sanguínea , Músculo Liso/inervação , Músculo Liso/fisiopatologia , Necrose , Perfusão/métodos , Fatores de TempoRESUMO
We developed a model of severe allergic inflammation and investigated the impact of airway and lung parenchyma remodelling on in vivo and in vitro respiratory mechanics. BALB/c mice were sensitized and challenged with ovalbumin in severe allergic inflammation (SA) group. The control group (C) received saline using the same protocol. Light and electron microscopy showed eosinophil and neutrophil infiltration and fibrosis in airway and lung parenchyma, mucus gland hyperplasia, and airway smooth muscle hypertrophy and hyperplasia in SA group. These morphological changes led to in vivo (resistive and viscoelastic pressures, and static elastance) and in vitro (tissue elastance and resistance) lung mechanical alterations. Airway responsiveness to methacholine was markedly enhanced in SA as compared with C group. Additionally, IL-4, IL-5, and IL-13 levels in the bronchoalveolar lavage fluid were higher in SA group. In conclusion, this model of severe allergic lung inflammation enabled us to directly assess the role of airway and lung parenchyma inflammation and remodelling on respiratory mechanics.
Assuntos
Asma/patologia , Asma/fisiopatologia , Hipersensibilidade Respiratória/patologia , Hipersensibilidade Respiratória/fisiopatologia , Mecânica Respiratória/fisiologia , Animais , Asma/induzido quimicamente , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Hiperplasia/patologia , Hipertrofia/patologia , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica/métodos , Agonistas Muscarínicos/farmacologia , Músculo Liso/patologia , Músculo Liso/ultraestrutura , Ovalbumina/efeitos adversos , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/patologia , Alvéolos Pulmonares/ultraestrutura , Eosinofilia Pulmonar/patologia , Hipersensibilidade Respiratória/induzido quimicamente , Mecânica Respiratória/efeitos dos fármacosRESUMO
A quantitative morphometric evaluation of the intramural plexus of the urinary bladder of adult and aged guinea-pigs was performed by histological analysis, scanning electron microscopy, and hystochemical methods, such as NADH-diaphorase and acetylcholinesterase (AChE). The round or oval shaped intramural neurons were revealed among the bundles of the smooth detrusor muscle in clusters containing a variable number of cells in the groups. In both adult control and aged animals, the ganglia were enveloped by a ganglionar capsule of connective tissue mainly composed of type I collagen fibers. The number of neurons NADH-diaphorase positives estimated in the intramural plexus was 1433+/-187.71 and 1107+/-120.67 in the adult control and aged groups, respectively. The perikaryon areas of the NADH-diaphorase neurons reactives ranged from 216.40 to 1809.30 microm(2) in adult control group and from 198.20 to 2096.25 microm(2) in aged group. The nuclear area showed an increase in aged animals. The number of AChE-positive neurons estimated in the intramural plexus was 3294.67+/-415 microm(2) in the adult control group and 1960.33+/-526 microm(2) in the aged group, showing a significant decrease in the latter group. This age-related morphological change in intramural neurons may contribute to changes in urinary bladder activities in the elderly.
Assuntos
Envelhecimento/fisiologia , Músculo Liso/citologia , Neurônios/fisiologia , Bexiga Urinária/citologia , Acetilcolinesterase/metabolismo , Fatores Etários , Animais , Di-Hidrolipoamida Desidrogenase/metabolismo , Cobaias , Microscopia Eletrônica de Varredura/métodos , Músculo Liso/ultraestrutura , Neurônios/metabolismo , Neurônios/ultraestruturaRESUMO
1. We evaluated changes in contractility of the guinea-pig isolated ileum, using intact segments and myenteric plexus-longitudinal muscle (MPLM) preparations, after several times (5-160 min) of ischemia in situ. 2. Intestinal ischemia was produced by clamping the superior mesenteric artery. Ischemic and nonischemic segments, obtained from the same guinea-pig, were mounted in organ baths containing Krebs-bicarbonate (K-B) solution, maintained at 37 degrees C and gassed with 95% O2/5% CO2. The preparations were allowed to equilibrate for 60 min under continuous superfusion of warm K-B solution and then electrically stimulated at 40 V (0.3 Hz, 3.0 ms). Thereafter, complete noncumulative concentration-response curves were constructed for acetylcholine (ACh), histamine (HIS), potassium chloride (KCl), and barium chloride (BaCl2). Mean Emax (maximal response) values were calculated for each drug. 3. Our study shows that alterations of chemically and electrically evoked contractions are dependent on ischemic periods. It also demonstrates that contractile responses of ischemic tissues to neurogenic stimulation decreases earlier and to a significantly greater extent than the non-nerve mediated responses of the intestinal smooth muscle. Contractile responses to smooth muscle stimulants were all similarly affected by ischemia. Electron microscopy images indicated necrotic neuronal death. The decrease in reactivity of ischemic tissues to electrical stimulation was ameliorated by dexrazoxane, an antioxidant agent. 4. We consider the guinea-pig isolated ileum as a useful model system to study the processes involved in neuronal ischemia, and we propose that the reduction in maximal responses to electrical stimulation is a useful parameter to study neuroprotection.
Assuntos
Acetilcolina/farmacologia , Histamina/farmacologia , Íleo/efeitos dos fármacos , Isquemia/fisiopatologia , Músculo Liso/efeitos dos fármacos , Animais , Compostos de Bário/farmacologia , Cloretos/farmacologia , Estimulação Elétrica , Cobaias , Íleo/fisiologia , Íleo/ultraestrutura , Técnicas In Vitro , Isquemia/etiologia , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/fisiologia , Músculo Liso/ultraestrutura , Plexo Mientérico/efeitos dos fármacos , Plexo Mientérico/ultraestrutura , Cloreto de Potássio/farmacologia , Fatores de TempoRESUMO
There are species-related anatomical differences in the ciliary muscle of the avian eye. The arrangement of muscular fibers in the avian eye is not well defined. To clarify this situation, we studied the architecture of ciliary muscle of Gallus domesticus by light and scanning electron microscopy (SEM). Our results showed the existence of three main muscular groups that we defined as anterior, posterior, and intermediary. These muscle divisions correspond to the description of the ciliary muscle as previously stated by Crampton (1813), Brucke, and Muller (1856). The striated fibers have a meridian orientation. The anterior and posterior muscular groups are inserted in the sclera, around the Schlemm's canal wall and ciliary process stroma. The vitreal intermediary muscle has fibers inserted in Schlemm's canal wall and ciliary process stroma. The framework of these muscular fibers may according to its insertions participate in the visual accommodation mechanism and outflow of the aqueous humor system.
Assuntos
Humor Aquoso/citologia , Corpo Ciliar/ultraestrutura , Olho/ultraestrutura , Músculo Liso/ultraestrutura , Animais , Humor Aquoso/fisiologia , Galinhas , Músculo Liso/cirurgiaRESUMO
We studied changes in mitochondrial morphology and function in the smooth muscle of rat colon. Under confocal microscopy, tissues loaded with potentiometric dye displayed rapid and spontaneous depolarization. Cyclosporin A (CsA), inhibitor of the permeability transition pore (PTP), caused an increase in mitochondrial membrane potential (DeltaPsim) in tissues from adult young animals. In aged rats these changes were not observed. This suggests that physiological activation of PTP in aged rats is reduced. Electron microscopy showed alterations of the mitochondrial ultrastructure in tissues from aged rats involving a decreased definition of the cristae and fragmentation of the mitochondrial membranes. We also detected an increase in apoptotic cells in the smooth muscle from aged animals. Our results show that the aging process changes PTP activity, the ability to maintain DeltaPsim and mitochondrial morphology. It is suggested that these can be associated with mitochondrial damage and cell death.
Assuntos
Envelhecimento/fisiologia , Apoptose , Mitocôndrias/ultraestrutura , Músculo Liso/citologia , Animais , Feminino , Marcação In Situ das Extremidades Cortadas , Microscopia Eletrônica , Músculo Liso/ultraestrutura , Ratos , Ratos WistarRESUMO
PURPOSE: To investigate the morphological effects of acute overdistension in the structure of the extracellular matrix of the bladder wall in rats. MATERIALS AND METHODS: The bladders of a group of 6 male Wistar rats were transurethrally overdistended for 3 hours. Another identical group (the control group) was only submitted to a sham operation. Specimens from the bladder dome were analyzed with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). RESULTS: LM--The control group bladders had a 4 to 5 layer urothelium, a lamina propria, and a smooth muscle layer with longitudinal and transversal fibers. The overdistended bladders presented an intense interstitial infiltrate in the lamina propria, and a less intense infiltrate among the smooth muscle fibers. TEM--The cells of the overdistended bladders had a significant amount of vacuoles, unlike the control bladders, where such vacuoles were scarce or absent. SEM--A delicate three-dimensional mesh of collagen fibrils was observed in the lamina propria of the bladder walls from the control group. Whilst for the control group this mesh consisted of distinct geometric structures, with mostly circular cellular spaces surrounded by the fibrils, the overdistended group showed evidence of distortion of the mesh, with flattened and elongated cellular spaces. CONCLUSIONS: Acute bladder overdistension induces structural modifications, altering the arrangement and interaction of collagen fibrils, as well as incipient tissue damage as edema in the lamina propria and smooth muscle layers.
Assuntos
Matriz Extracelular/fisiologia , Músculo Liso/fisiologia , Bexiga Urinária/fisiologia , Animais , Matriz Extracelular/ultraestrutura , Masculino , Microscopia Eletrônica de Varredura , Músculo Liso/citologia , Músculo Liso/ultraestrutura , Ratos , Estresse Mecânico , Bexiga Urinária/citologia , Bexiga Urinária/ultraestruturaRESUMO
Substance P (SP) and its receptors NK1 and NK2 are widely expressed in the intestinal wall by neurones, interstitial cells of Cajal (ICC) and smooth muscle cells. Changes in SP and/or its NK receptors have been documented during experimental inflammation in animals or inflammatory bowel diseases in humans, but the data concern the acute phase of the inflammatory process. We determined immunohistochemically whether NK receptors and SP were altered in the muscle coat during jejunal inflammation induced by the nematode Nippostrongylus brasiliensis and whether these alterations persisted when inflammation had spontaneously resolved 30 days postinfection. An ultrastructural analysis was also conducted on ICC, nerves and muscle. At day 14, when inflammation peaked, there was a reduction in NK1 receptors in myenteric neurones and in SP-immunoreactive nerve endings. There were also ultrastructural anomalies in synaptic vesicles and NK2 receptor loss in the circular muscle layer. The SP decrease persisted at day 30, whereas neurones and circular muscle cells re-expressed NK1 and NK2 receptors, respectively. The ICC at the deep muscular plexus, located near to the inflammatory site, underwent alterations leading to their complete loss at day 30. These morphological changes are probably associated with impairment in tachykinergic control of jejunal functions leading to the alterations of motility and sensitivity to distension already described in these animals.
Assuntos
Jejuno/patologia , Nippostrongylus , Receptores da Neurocinina-1/ultraestrutura , Receptores da Neurocinina-2/ultraestrutura , Infecções por Strongylida/metabolismo , Infecções por Strongylida/patologia , Animais , Células do Tecido Conjuntivo/metabolismo , Células do Tecido Conjuntivo/ultraestrutura , Imuno-Histoquímica , Inflamação/metabolismo , Inflamação/parasitologia , Inflamação/patologia , Jejuno/inervação , Jejuno/metabolismo , Jejuno/ultraestrutura , Masculino , Músculo Liso/inervação , Músculo Liso/metabolismo , Músculo Liso/ultraestrutura , Peroxidase/metabolismo , Ratos , Ratos Wistar , Infecções por Strongylida/parasitologia , Substância P/análiseRESUMO
We investigated the structural organization of the choroid especially with regard to the presence of extravascular smooth muscle (EVSM) cells in albino rabbits. The eyes were fixed by intracardiac perfusion and processed for light, confocal, and electron microscopy. An unlabeled monoclonal antibody against alpha-actin of smooth muscle and a horseradish-peroxidase-conjugated secondary antibody were used for immunodetection of smooth muscle actin by light microscopy. For confocal microscopy, whole mount choroids were immunostained with a fluorescein isothiocyanate-conjugated (FITC) antibody. Our investigations revealed that the choroidal vessels are enveloped by bundles of EVSM. In contrast to the circular orientation of the smooth muscle cells of the tunica media of the choroidal vessels, the cells of the EVSM system were oriented longitudinally along the external surface of the vessel wall. The EVSM cells were strongly immunopositive for smooth muscle alpha-actin and exhibited a green fluorescence of the FITC-labeled anti-alpha-actin antibody. Individual cells were elongated and spindle-shaped, had the usual ultrastructural features of smooth muscle cells and, in places, were organized as 20 layers. EVSM cells were present throughout the thickness of the choroid, but not between the fenestrated endothelial lining of the choriocapillaris and Bruch's membrane, and extended from the optic nerve to the ciliary body where they merged with the ciliary muscles. Based on the three dimensional organization, immunoreactivity, and cellular and subcellular features of the EVSM system as well as information in the literature, we hypothesize that, functionally, this system, in conjunction with the choroidal vasculature, contributes to the myogenic control of choroidal blood flow and tissue volume, and also affects the intraocular pressure as well as the refractive and accommodative state of the eye.
Assuntos
Corioide/anatomia & histologia , Músculo Liso/ultraestrutura , Actinas/imunologia , Animais , Anticorpos Monoclonais , Desmina/imunologia , Fluoresceína-5-Isotiocianato , Peroxidase do Rábano Silvestre , Masculino , Microscopia Confocal , Microscopia Eletrônica , Músculo Liso/imunologia , CoelhosRESUMO
Diabetes mellitus is characterized by anatomical and functional alterations of the intestinal tract. However, the aetiology of these disturbances remains unclear. The aim of the present work was to investigate the effects of diabetes on the expression of laminin-1 and fibronectin in the small intestine of Streptozotocin (STZ)-induced diabetic rats. The Western immunoblotting of the extracts from the small intestine revealed that experimental diabetes resulted in a marked increase in the intensity of the bands corresponding to laminin-1 and fibronectin. Immunohistochemical studies demonstrated a strong labelling to these two extracellular matrix (ECM) proteins in the small intestine of diabetic rats, mainly localized in the smooth muscle layer. These results occur together with a thickening of the basement membrane (BM) of the smooth muscle cells, demonstrated by transmission electron microscopy (TEM). We propose that the accumulation of ECM proteins in the smooth muscle layer may be an effect mediated by hyperglycaemia, since insulin treatment of diabetic rats reversed this accumulation. These results could provide information on the potential role of the ECM in the intestine, an organ which is known to exhibit important alterations in diabetes.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Intestino Delgado/metabolismo , Músculo Liso/metabolismo , Animais , Membrana Basal/metabolismo , Membrana Basal/patologia , Membrana Basal/ultraestrutura , Glicemia/metabolismo , Western Blotting , Peso Corporal , Diabetes Mellitus Experimental/patologia , Fibronectinas/metabolismo , Intestino Delgado/patologia , Intestino Delgado/ultraestrutura , Laminina/metabolismo , Masculino , Músculo Liso/patologia , Músculo Liso/ultraestrutura , Tamanho do Órgão , Ratos , Ratos Sprague-DawleyRESUMO
Previous studies have shown that chronic administration of oestrogen during postnatal rat development dramatically reduces the total content of noradrenaline in the uterine horn, abolishes myometrial noradrenergic innervation and reduces noradrenaline-fluorescence intensity of intrauterine perivascular nerve fibres. In the present study we analysed if this response is due to a direct and selective effect of oestrogen on the uterine noradrenaline-containing sympathetic nerves, using the in oculo transplantation method. Small pieces of myometrium from prepubertal rats were transplanted into the anterior eye chamber of adult ovariectomised host rats. The effect of systemic chronic oestrogen treatment on the reinnervation of the transplants by noradrenaline-containing sympathetic fibres from the superior cervical ganglion was analysed on cryostat tissue sections processed by the glyoxylic acid technique. In addition, the innervation of the host iris was assessed histochemically and biochemically. The histology of the transplants and irises was examined in toluidine blue-stained semithin sections. These studies showed that after 5 wk in oculo, the overall size of the oestrogen-treated transplants was substantially larger than controls, and histology showed that this change was related to an increase in the size and number of smooth muscle cells within the transplant. Chronic oestrogen treatment did not provoke trophic changes in the irideal muscle. Histochemistry showed that control transplants had a rich noradrenergic innervation, associated with both myometrium and blood vessels. Conversely, in oestrogen-treated transplants only occasional fibres were recognised, showing a reduced NA fluorescence intensity. No changes in the pattern and density of innervation or in the total content of noradrenaline of the host irises were detected after chronic exposure to oestrogen. We interpreted these results to indicate that the effects of oestrogen on uterine noradrenaline-containing sympathetic nerves are neither selective or direct, but result from an interaction between sympathetic nerve fibres with the oestradiol-primed uterine tissue. A potential effect of oestrogen on the neurotrophic capacity of the uterus is discussed.
Assuntos
Estradiol/farmacologia , Miométrio/inervação , Regeneração Nervosa/efeitos dos fármacos , Gânglio Cervical Superior/fisiologia , Animais , Câmara Anterior , Feminino , Histocitoquímica/métodos , Iris/inervação , Músculo Liso/efeitos dos fármacos , Músculo Liso/ultraestrutura , Miométrio/transplante , Fibras Nervosas/ultraestrutura , Norepinefrina/análise , Ovariectomia , Ratos , Ratos WistarRESUMO
1. Age-related changes in the reactivity of postsynaptic alpha-adrenoceptors of isolated portions (epididymal and prostatic) and in whole vas deferens have been studied using 4, 12 and 20 month-old rats. 2. The pD2 values for adrenaline-induced contractions were reduced in the epididymal portion and whole vas deferens of middle-aged and old animals, but not in the prostatic portion. No age related change to phenylephrine or clonidine sensitivity was observed. 3. pA2 values of prazosin and yohimbine were not changed by aging in any preparation. Phentolamine pA2 values were reduced in the epididymal portion and in the whole vas deferens when adrenaline, but not when phenylephrine concentration-response curves were displaced by the antagonist. The mean pA2 value of yohimbine (6.78) indicates that this antagonist blocks alpha(1)-adrenoceptors in the rat vas deferens. 4. The data presented here suggest that age-related decreases in the sensitivity to adrenaline and phentolamine (when measured by displacing adrenaline concentration-effect curves) in the whole vas deferens are probably due to a variation in the proportion of alpha(1)-adrenoceptor subtypes in the epididymal portion of the rat vas deferens.
Assuntos
Envelhecimento/fisiologia , Epididimo/ultraestrutura , Próstata/ultraestrutura , Receptores Adrenérgicos alfa/fisiologia , Ducto Deferente/ultraestrutura , Agonistas alfa-Adrenérgicos/metabolismo , Agonistas alfa-Adrenérgicos/farmacologia , Antagonistas Adrenérgicos alfa/metabolismo , Antagonistas Adrenérgicos alfa/farmacologia , Envelhecimento/metabolismo , Animais , Epididimo/efeitos dos fármacos , Epinefrina/farmacologia , Cinética , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/ultraestrutura , Fenilefrina/farmacologia , Próstata/efeitos dos fármacos , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa/metabolismo , Ducto Deferente/efeitos dos fármacosRESUMO
Protons generated inside the cells during metabolic activity have to be extruded through active mechanisms from the intracellular to the extracellular space. One of the systems involved in proton transport across membranes are the V-ATPases, which are oligomeric complexes that have been found in several subcellular organelles energizing such organelle through a proton gradient and a membrane potential. In this paper, a V-ATPase activity has been described at the plasma membranes fractions isolated from airway smooth muscle. This activity was measured as a Cl- stimulated Mg2+ ATPase. This Cl- activating effect was also shared by others halogens as I- and Br- but not F-. This Cl- stimulated ATPase is a nucleotide triphosphatase being unable to hydrolyze mono and dinucleotides. The divalent cations showed the following sequence of activation (Mg2+ > Mn2+ > Ca2+) of the Cl- activated Mg2+ ATPase. This Cl- stimulated Mg2+ ATPase was insensitive to ouabain, vanadate, sodium azide and rutamicina. NEM (N-ethylmaleimide) partially inhibited this activity but a complete inhibition was observed with p-CMB (p-chloromercurbenzoate ). Several specific proton transport inhibitors were employed to show the presence of a H+ pump activity. Thus, the strong inhibition induced by DCCD suggest the existence of hydrophobic subunits related to a proton channel. In addition, protonophores as 1799 and FCCP stimulated the Cl- stimulated ATPase indicating the presence of a H+ pump in these plasma membranes vesicles. The chloride requirement could be explained by the existence of a chloride conductor coupled to the proton pump (H+ ATPase-type V) due to the inhibitory effect of duramycin.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Músculo Liso/fisiologia , Bombas de Próton/fisiologia , ATPases Translocadoras de Prótons/metabolismo , Ânions/farmacologia , Antibacterianos/farmacologia , ATPase de Ca(2+) e Mg(2+)/antagonistas & inibidores , ATPase de Ca(2+) e Mg(2+)/metabolismo , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Membrana Celular/metabolismo , Cloromercurobenzoatos/farmacologia , Dicicloexilcarbodi-Imida/farmacologia , Células Eucarióticas/ultraestrutura , Humanos , Músculo Liso/ultraestrutura , Peptídeos , ATPases Translocadoras de Prótons/antagonistas & inibidoresRESUMO
A sequential histologic, ultrastructural and immuno pathologic study was carried out in the Selye's inflammatory pouch model to observe extracellular matrix and cellular changes during granulation tissue formation. Besides changes involving different components of the connective tissue, it was observed that collagen resorption occurred under a biphasic process. At an early phase (3rd to 15th day), in which exudative inflammatory changes predominated, signs of collagen synthesis and degradation were seen simultaneously. Extracellular breakdown and internalization of collagen fragments within fibroblasts and myofibroblasts were observed. Later on (30th to 60th day), changes affecting collagen had a different ultrastructural appearance. Collagen fragmentation, focal "lytic" and "electron dense" changes occurred in the extracellular space specially at the periphery of fibroblasts, myofibroblasts and smooth muscle cells. Collagen degradation, thus seems to be a continuous process in granulation tissue, occurring with different morphologies at different times.
Assuntos
Colágeno/metabolismo , Tecido de Granulação/metabolismo , Animais , Óleo de Cróton/administração & dosagem , Matriz Extracelular/metabolismo , Matriz Extracelular/ultraestrutura , Feminino , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Tecido de Granulação/citologia , Tecido de Granulação/ultraestrutura , Injeções Subcutâneas , Masculino , Microscopia Eletrônica , Músculo Liso/citologia , Músculo Liso/metabolismo , Músculo Liso/ultraestrutura , RatosRESUMO
The development of the smooth muscle in the genital tract of the female mouse was studied by light and electron microscopy before and after birth. These studies showed that: a) between 13 days of fetal development and 2 days after birth the cells surrounding the Mullerian duct were undifferentiated and showed a fibroblast-like appearance; b) between 3 and 10 days after birth the cells acquired several characteristics of smooth muscle but they did not seem fully mature; c) between 30 and 180 days after birth the cells acquired a mature appearance; and d) the Wolffian nerve reached the Mullerian duct surrounding tissue before the start of smooth muscle differentiation.