Ghrelin role in the modulation of testicular function in obesity and fasting- There exists an association between the body energy reserve and the reproductive function. Body energy reserve is necessary for the appropriate puberal development, growth and fertility. The gonadal axis is altered by nutritional disorders such as obesity, malnutrition, and anorexia. Recently, different molecular signals involved in the integrating control between the reproduction and the energy homeostasis have been described. Leptin, a hormone mainly synthesized in adipocytes, and Ghrelin, in stomach, act at central level, exerting anorexigenic and orexigenic actions through hypothalamic receptors. Leptin inhibits whereas Ghrelin stimulates NPY. We have studied Leptin levels in pre- and post puberal male rats. Direct effects of Leptin and Ghrelin on steroidogenic testicular function and OBRb receptor expression in Leydig cells were also evaluated in our Laboratory. Ours and previous results suggest that the direct action of Ghrelin on male gonad would depend on Leydig cell differentiation.

It is our intention to extend our studies on the action mechanisms of Ghrelin on the testes of prepuberal and adult rats with nutritional disorders. Two animal models are used: i) pseudo-obesity induced by monosodic glutamate (MSG) administration, and ii) 96 hours fasting. We will evaluate the influence of these two states on Ghrelin and its specific receptor expression and localization in different testicular cells. The effect of different concentrations of Ghrelin on androgen production and on StAR protein and key steroidogenic enzyme expression will be also studied.

 

Staff

SUESCUN, María Olga , Investigador Independiente CONICET - Jefe de Laboratorio
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CABRAL, Agustina Soledad, Becario de Estudio CICPBA
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