Histologic effect of mitomycin C on strabismus surgery in the rabbit

PURPOSE. TO evaluate the efficiency of mitomycin C (MMC) in limiting the postoperative inflammatory response and scarring after strabismus surgery. METHODS. A prospective, two-stage, masked, controlled trial was conducted. In the first stage, the inflammatory response at the extraocular muscle reattachment site was increased after inferior rectus recession in eight rabbits. In the second stage, MMC (0.4 mg/ml) was applied during surgery to the eyes of 22 rabbits with inferior rectus recession. As a control, contralateral eyes were treated with saline solution. Seven weeks later, exenteration was performed, and the sites of muscle reattachment were processed for histologic examinations. The sums of the areas of the granulomas in the extraocular muscle reattachment sires of control and treated eyes were compared. RESULTS. There was no significant inhibitory effect of MMC on the inflammatory response of treated eyes compared with that of control eyes. CONCLUSIONS. The intraoperative use of MMC (0.4 mg/ml) was not effective in controlling the postoperative inflammatory response in rabbit eyes after extraocular muscle surgery. These data do not support the hypothesis that MMC reduces postoperative adhesions after strabismus surgery.O TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE FEVEREIRO DE 2015.41113399340

Stereology and ultrastructure of the seminal vesicle of C57/BL/6J mice following chronic alcohol ingestion

Excessive alcohol consumption causes metabolic changes and pathologic alterations in testes and accessory sex organ in different animal species. The aim of the present study was to evaluate the macroscopic, histologic and ultrastructural alterations provoked by chronic ingestion of different ethanol concentrations over increasing periods of time on the secretory epithelium of the seminal vesicle of C57/BL/6J mice in using stereological methods. Sixty male adult mice were divided into three experimental groups: Control, Alcoholic 25% and Alcoholic 35%, respectively, receiving tap water and tap water containing ethanol diluted to 25 and 35degrees Gay Lussac. All mice were fed with the same solid diet. After 150 and 250 days of treatment the animals were sacrificed and the seminal vesicles were collected and processed for light and transmission electron microscopy. The cellular, cytoplasmic and nuclear volumes and the area density of autophagic and secretory vacuoles were measured. The histologic alterations observed in the alcoholic mice consisted of a reduction in epithelial size and cell volume, with maintenance of the same nuclear and cytoplasmic ratio as verified in the control groups. The ultrastructural alterations were: increased density of dense body area, decreased density of secretory granule area, and dilated rough endoplasmic reticulum and Golgi cisternae. We conclude that chronic ethanol ingestion causes depleting morphologic alterations in the epithelial cells of the seminal vesicle and negatively affects the secretory process of this gland. (C) 2002 Elsevier Science Ltd. All rights reserved.34317718

Enhanced airways responsiveness in rats depleted of sensory neuropeptides by neonatal capsaicin treatment

This study aimed to investigate the in vivo and in vitro reactivity of airway smooth muscle in rats depleted of sensory neuropeptides by treatment with capsaicin at neonatal stage. Wistar rats were neonatally injected with either capsaicin (50 mg/kg, s.c., 2nd day of life) or its vehicle (10% ethanol and 10% Tween 80, in 0.9% w/v NaCl solution) and used at adult ages (60-70 days later). Analysis of the lungs showed a higher number of infiltrating neutrophils, eosinophils and mononuclear cells into the peribronchiolar regions of capsaicin-pretreated rats compared to vehicle group. This was associated with a higher contraction index of bronchiolar wall in the capsaicin group. The in vitro tracheal reactivity in response to methacholine (full muscarinic agonist) and pilocarpine (partial muscarinic agonist) was also significantly higher in capsaicin-pretreated rats compared to vehicle group. In conclusion, the neuropeptide depletion by capsaicin neonatal treatment lead to marked contraction of the rat airways at adult age, suggesting a protective role for C fibers in the lungs. (C) 2003 Elsevier B.V. Ireland Ltd. All rights reserved

Pravastatin reduces myocardial lesions induced by acute inhibition of nitric oxide biosynthesis in normocholesterolemic rats

Pravastatin is useful in restoring endothelium-dependent relaxation in hypercholesterolemic animals. A single intravenous bolus injection of N-omega-nitro-L-arginine methyl ester (L-NAME), a non-specific inhibitor of NO synthase, causes myocardial necrosis and reduces coronary flow in rats. Since rats do not develop hypercholesterolemia and atherosclerosis, we have tested the hypothesis that pravastatin protects the heart from myocardial lesions induced by L-NAME in the absence of alterations in cholesterol levels and plaque formation. Male Wistar rats fed standard chow were divided into four groups: CONTROL (n=14) - rats that received tap water alone for 18 days; L-NAME (n=14) - rats that received L-NAME (15 mg/kg, i.v.) on the 14th day of the study; PRAVASTATIN (n=11) - rats that received pravastatin (6 mg/kg/day) in their drinking water for 18 days; PRAVASTATIN+L-NAME (n=12) - rats that received pravastatin (6 mg/kg/day) and L-NAME (15 mg/kg, i.v.) as indicated in the preceding groups. At the end of 18 days, the rats were sacrificed and the hearts removed for stereological analysis by light microscopy. Plasma nitrate/nitrite and thromboxane B-2 concentrations were determined immediately before and after L-NAME administration. Pravastatin prevented the ischemic lesions induced by the acute inhibition of NO biosynthesis (the area of myocardial lesions in the L-NAME group was greater than in the Pravastatin+L-NAME group: 101.6 mum(2) vs. 1.2 mum(2), respectively; P <0.0001) and markedly increased the plasma nitrate/nitrate concentrations, even before L-NAME administration. There were no significant changes in the plasma thromboxane B-2 concentrations. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.794170021522

Modulation of coronary flow and cardiomyocyte size by sensory fibers

Cardiac tissue is densely innervated by sensory neurons that an believed to play important modulatory roles in cardiac functions. In this study, pretreatment of neonate mts with capsaicin was performed. In adult rats, cardiomyocyte size and amount of fibrous tissue in left ventricles as well as in vitro coronary flow were evaluated, the chronotropic and inotropic responses to beta-adrenoceptor agonists (norepinephrine and isoproterenol), muscarinic agonists (carbachol and pilocarpine), and calcitonin gene-related peptide (CGRP) were also investigated with the use of the isolated right atria preparation. Capsaicin pretreatment significantly (P<0.05) reduced both basal coronary flow (18% reduction) and cardiomyocyte size (34% reduction) without affecting the amount of fibrous tissues in the left ventricles. The positive inotropic and chronotropic effects in response to norepinephrine in the isolated rat heart did not significantly differ between control and capsaicin-treated rats, Similarly, the positive chronotropic effects in response to norepinephrine, isoproterenol, and CGRP as well as the negative chronotropic responses to carbachol and pilocarpine in the isolated light atria were not affected by capsaicin pretreatment, Our data are consistent with the suggestion that reductions of both basal coronary flow and cardiomyocyte size seen in hearts from capsaicin-pretreated rats may be consequences of CGRP depletion. The cardiomyocyte size reduction produced by capsaicin treatment may be related to a modulatory role of CGRP as a growth factor