Effects castration and hormonal replacement in the rat urinary bladder, structural, ultrastructural and biochemical analysis

Evidências recentes em animais e humanos sugerem que níveis adequados de testosterona são necessários para as funções adequadas de diversos órgãos do sistema urogenital, incluindo a bexiga urinária. Estudos sobre os efeitos da testosterona na estrutura da parede da bexiga são raros. Portanto, o objetivo do presente trabalho é avaliar através de métodos qualitativos e quantitativos, as alterações estruturais da parede vesical de ratos submetidos à castração cirúrgica, bem como o papel da reposição hormonal na reversão das possíveis alterações estruturais. Foram usados 24 ratos machos Sprague-Dawley com aproximadamente 12 semanas de idade. Os animais foram divididos em 3 grupos compostos de 8 animais cada e tratados como a seguir. C = Grupo Castrado os animais foram submetidos a orquiectomia e sacrificados após 2 meses, S = Grupo Simulado os animais foram submetidos a operação simulada e sacrificados após 2 meses, T = Grupo Testosterona os animais foram submetidos a castração e após 1 mês foram submetidos a reposição hormonal com undecanoato de testosterona em dose única subcutânea de 100 mg/kg (T) e após 1 mês da reposição hormonal foram sacrificados. Foram realizadas análises quantitativa e qualitativa do colágeno (usando histoquímica, histomorfometria, bioquímica e microscopia eletrônica de varredura), e análise histomorfométrica do músculo liso e das fibras do sistema elástico na parede da bexiga em controles e em ratos submetidos apenas a castração, e em ratos submetidos a castração e reposição hormonal. A análise morfométrica da altura do urotélio não apresentou diferença entre os grupos. Não houve diferença significativa na análise quantitativa do colágeno, tanto por histomorfometria quanto por bioquímica. Entretanto, a análise qualitativa mostrou diferenças do colágeno no grupo castrado quando comparado aos controles e aos ratos com reposição hormonal. Existiu uma diminuição significativa nos valores absolutos das fibras do sistema elástico no grupo castrado. Por outro lado, o músculo liso apresentou um aumento significativo na massa muscular por densidade de área nos ratos castrados; entretanto, a contagem dos núcleos das células musculares não apresentou variação entre os grupos, demonstrando que o aumento foi devido a hipertrofia muscular e não por aumento do número de células. Interessantemente, a reposição hormonal com testosterona foi capaz de reverter todas as alterações observadas. Os resultados sugerem que a reposição hormonal, mesmo quando instituída em fase tardia, é efetiva na reversão das alterações da parede da bexiga produzidas por hipogonadismo secundário.Recent evidences in animals and humans have suggested that adequate levels of testosterone are necessary to adequate functions of diverse organs of the urogenital system, including the urinary bladder. Studies on the effects of testosterone in the bladder wall structure are rare. Therefore, the objective of the present study is to evaluate, through qualitative and quantitative methods, the structural alterations in the bladder wall of rats submitted to surgical castration as well as the role of hormonal replacement in reversing the possible structural alterations. We used 24 male Sprague-Dawley rats that were approximately 12 weeks of age. The animals were divided into 3 groups composed of 8 animals each and treated as follows. Group C = group that underwent orchiectomy and were sacrificed after 2 months, Group S = sham group sacrificed after 2 months, and Group T = group that underwent orchiectomy, and after 1 month underwent testosterone replacement with a subcutaneous single dose of testosterone undecanoate at 100 mg/kg (T) and after 1 month of hormonal replacement, the animals were sacrificed. We performed a qualitative and quantitative analysis of collagen (by using histochemistry, histomorphometry, biochemistry, and scanning electron microscopy), and a histomorphometric analysis of smooth muscle and elastic system fibers in bladder wall of controls and rats submitted to orchiectomy alone and with hormonal replacement. The histomorphometric analysis on the epithelial height did not show differences among the groups. There was no statistically significant difference in the quantitative analysis for collagen, both by histomorphometry and biochemistry. Nevertheless, the qualitative analysis showed differences in collagen in the castrated group, when compared to controls and to rats with hormonal replacement. There was a significant decrease in the absolute values of elastic system fibers in the castrated group. On the other hand, the smooth muscle presented a significant increase in muscular mass by density of area in castrated rats; nevertheless, the counting of muscle cells nuclei did not present variation among the groups, demonstrating that this increase was due to cellular hypertrophy rather than by an increase in cells number. Interestingly, the hormonal replacement with testosterone was able to reverse all alterations observed. The results suggest that hormonal replacement, even when instituted at a late stage, is effective in reversing the bladder wall alterations produced by secondary hypogonadism

Effect of a high-fat diet on the rat bladder wall and bioactive action of Brazil nut oil

ABSTRACT High-fat diet-induced obesity is associated with metabolic disorders. The Brazil nut has bioactive substances and has been used to control the damage caused by obesity in several organs. The work intended to show the damage caused by high-fat diet in the bladder wall and if the Brazil nut oil added to the diet could ameliorate or reverse this effect. Sixty-day-old rats were divided into two groups: C (control, n = 30) and HF (high-fat, n = 30) diets. At 90 days, 10 animals of each group were sacrificed. The others were divided into 4 groups: C and HF (animals that maintained their previous diet, n = 10 for each group) and C / Bno and HF / Bno (animals whose control or high-fat diet was supplemented by Brazil nut oil, n = 10 for each group). Sacrifice occurred at 120 days, and the bladders were removed and analyzed. Epithelial height was increased in the HF compared to the C group. In contrast, the C / Bno had a lower epithelial height compared to the others. The percentage of collagen between the detrusor muscle fibers was significantly greater in C / Bno, HF and HF / Bno than in control group. The HF had a larger muscle fiber diameter than the C group, while the C / Bno presented lower values than the HF and HF / Bno groups. HF diets induced bladder wall damage. These changes in the rat's bladder wall were partially reversed by the Bno