Pituitary-ovarian dysfunction in rats with induced nephrotic syndrome

The reproductive hormonal profile was evaluated in female rats with experimental nephrotic syndrome induced with a single subcutaneous dose of puromycin aminonucleoside (PAN). Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P4), testosterone and 17 beta-estradiol (E2) were determined sequentially in control and experimental groups on days 1, 3, 7 and 10 after PAN administration. Prolactin levels were also assessed on day 10. In both groups, vaginal smears were taken daily throughout the study to evaluate cyclic histological changes. At the end of the experiment the histological appearance of the ovaries was evaluated by light microscopy. Nephrotic rats had a rapid loss of the estrous cycle starting on day 4, which set them at diestrus. At the same time the hormonal evaluation indicated a gradual decrease in E2, LH and P4 concentrations, starting from days 3, 7 and 10, respectively. No significant changes were noted in FSH or testosterone values. Besides, on day 10, prolactin concentrations remained unmodified. Even though most hormonal levels were found low on day 10, all values except E2 (undetectable) corresponded to the interval reported for the diestrus phase. Likewise, histological examination of ovarian tissue from nephrotic rats showed a considerable increase in the number of atretic follicles. These findings indicate that female rats with nephrotic syndrome develop an important endocrine dysfunction that probably involves steroidogenic tissues (ovary and/or adrenal gland), and suggest the existence of a hypothalamic-hypophyseal impairment.