Impacto da dieta hipercalórica sobre parâmetros reprodutivos de ratos machos adultos
Arquivos
Data
2018-12-05
Autores
Cabral, Aline Xavier 
Orientadores
Perobelli, Juliana Elaine
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O sobrepeso e a obesidade são atualmente dois dos maiores problemas de saúde de ordem mundial. Caracterizada pelo acúmulo excessivo de gordura nas células do tecido adiposo, a obesidade é fator relacionado a diversas doenças metabólicas e morfológicas, incluindo infertilidade masculina, pelo fato dos adipócitos serem responsáveis pela síntese e liberação de leptina, proteína que tem como função diminuir o apetite e aumentar o gasto energético, mas que também atua na regulação do eixo hipotalâmico- hipofisário-gonadal. Sabe-se que a leptina pode atuar na modulação do comportamento das células de Sertoli, conversão da testosterona em estradiol e na liberação de FSH. Com o objetivo de investigar os efeitos da obesidade sobre a saúde reprodutiva masculina, o presente estudo analisou as alterações histomorfométricas de testículos e epidídimos de ratos machos adultos expostos à dieta hipercalórica, bem como possíveis alterações nos níveis plasmáticos de testosterona, nas contagens espermáticas e na expressão de receptores endócrinos nesses tecidos. Para tanto, ratos da linhagem Wistar, machos, adultos, foram distribuídos em dois grupos - controle (C, n=7) e high-fat (HF, n=7), os quais receberam dieta normal e hipercalórica, respectivamente, durante 14 semanas, do dia pós-natal (DPN)98 ao DPN 196. Os animais foram avaliados quanto à evolução da massa corpórea, glicemia, triglicerol e colesterol total durante o tratamento. No DPN 196 os animais foram eutanasiados e avaliados quanto aos parâmetros reprodutivos. Os resultados obtidos mostraram redução estatisticamente significativa na massa corporal final e na massa absoluta e/ou relativa dos órgãos reprodutivos dos animais do grupo High Fat. Nas análises morfométricas observamos uma redução no número de células de Sertoli e aumento no diâmetro do túbulo seminífero do grupo High Fat em comparação ao controle. A avaliação histopatológica revelou uma redução no montante de espermatozoides na luz dos epidídimos, porém não foram encontradas alterações nos testículos dos animais tratados em comparação ao controle. Na contagem de espermatozoides observamos redução estatisticamente significante no número de espermatozoides nos testículos e epidídimos, na produção diária de espermatozoides e no tempo de trânsito espermático na cabeçacorpo dos epidídimos. Os níveis de testosterona foram similares entre os grupos experimentais. Os resultados obtidos evidenciam importantes alterações na eficiência da espermatogênese e maturação espermática. Com isso, é possível concluir que o sobrepeso/obesidade alteraram negativamente importantes parâmetros reprodutivos, sugerindo possível prejuízo à fertilidade masculina. Faz-se necessário melhor investigar o papel da sinalização dos receptores androgênicos e estrogênicos nesse processo.
Overweight and obesity are currently two of biggest health problems in the world. Characterized by excessive fat accumulation in adipose tissue cells, obesity is a factor related to several metabolic and morphological diseases, including male infertility, due to the fact that adipocytes are responsible for the synthesis and release of leptin, a protein that decreases appetite and increase energy expenditure, but also acts on the regulation of the hypothalamic-pituitary-gonadal axis. It is known that leptin can act in the modulation of Sertoli cells function, conversion of testosterone to estradiol and in the release of FSH. In order to investigate the effects of obesity on male reproductive health, the present study analyzed the histomorphometric alterationsin testes and epididymis of adult male rats exposed to hypercaloric diet, as well as possible alterations in plasma testosterone levels, sperm counts and expression of endocrine receptors in these tissues. Male Wistar rats were distributed into two groups: control (C, n = 7) and high-fat (HF, n = 7), who received normal and hypercaloric diets, respectively, for 14 weeks, from postnatal day (PND) 98 to PND 196. The animals were evaluated regarding body weight, glycemia, triglycerol and total cholesterol during treatment. At PND 196, the animals were euthanized and evaluated for reproductive parameters. The obtained results showed a statistically significant reduction in final body weight and in absolute and/or relative mass of reproductive organs of High Fat group. In morphometric analyzes, it was observed a reduction in the number of Sertoli cells and an increase in the diameter of the seminiferous tubule of High Fat group in comparison to control. Histopathological evaluation revealed a reduction in the number of spermatozoa in epididymal lumen, but no changes were found in the testes of treated animals compared to control. In sperm counts, it was observed a statistically significant reduction in sperm number in testis and epididymis, in daily sperm production and in sperm transit time through caput/corpus epididymis. Testosterone levels were similar between the experimental groups. The obtained results evidenced important changes in the efficiency of spermatogenesis and sperm maturation. Thus, it is possible to conclude that overweight/obesity negatively altered important reproductive parameters, suggesting possible male fertility impairment. It is necessary to better investigate the role of androgen and estrogen receptor signaling in thisprocess.
Overweight and obesity are currently two of biggest health problems in the world. Characterized by excessive fat accumulation in adipose tissue cells, obesity is a factor related to several metabolic and morphological diseases, including male infertility, due to the fact that adipocytes are responsible for the synthesis and release of leptin, a protein that decreases appetite and increase energy expenditure, but also acts on the regulation of the hypothalamic-pituitary-gonadal axis. It is known that leptin can act in the modulation of Sertoli cells function, conversion of testosterone to estradiol and in the release of FSH. In order to investigate the effects of obesity on male reproductive health, the present study analyzed the histomorphometric alterationsin testes and epididymis of adult male rats exposed to hypercaloric diet, as well as possible alterations in plasma testosterone levels, sperm counts and expression of endocrine receptors in these tissues. Male Wistar rats were distributed into two groups: control (C, n = 7) and high-fat (HF, n = 7), who received normal and hypercaloric diets, respectively, for 14 weeks, from postnatal day (PND) 98 to PND 196. The animals were evaluated regarding body weight, glycemia, triglycerol and total cholesterol during treatment. At PND 196, the animals were euthanized and evaluated for reproductive parameters. The obtained results showed a statistically significant reduction in final body weight and in absolute and/or relative mass of reproductive organs of High Fat group. In morphometric analyzes, it was observed a reduction in the number of Sertoli cells and an increase in the diameter of the seminiferous tubule of High Fat group in comparison to control. Histopathological evaluation revealed a reduction in the number of spermatozoa in epididymal lumen, but no changes were found in the testes of treated animals compared to control. In sperm counts, it was observed a statistically significant reduction in sperm number in testis and epididymis, in daily sperm production and in sperm transit time through caput/corpus epididymis. Testosterone levels were similar between the experimental groups. The obtained results evidenced important changes in the efficiency of spermatogenesis and sperm maturation. Thus, it is possible to conclude that overweight/obesity negatively altered important reproductive parameters, suggesting possible male fertility impairment. It is necessary to better investigate the role of androgen and estrogen receptor signaling in thisprocess.
Descrição
Citação
CABRAL, Aline Xavier. Impacto da dieta hipercalórica sobre parâmetros reprodutivos de ratos machos adultos. 2018. 41 f. Trabalho de conclusão de curso de graduação (Educação Física) - Instituto de Saúde e Sociedade, Universidade Federal de São Paulo, Santos, 2018.