Fertility diminution in female rats with experimental chronic nephrosis

Chronic aminonucleoside nephrosis in rats is an experimental analogue of hu man focal segmental glomerulosclerosis. This study was undertaken to define the effects of chronic nephrosis on the pituitary-ovarian axis and on fert ility. Chronic nephrosis was induced by puromycin aminonucleoside and follo wed for 112 days. The estrous cycle was evaluated daily in all rats, wherea s biochemical parameters, hormonal concentrations, and fertility were measu red on Days 7, 14, 28, 56, 84, and 112 (n = 8). Animals were divided in fou r experimental groups: A, 8, C, and D. Group A was used to determine LH, FS H, progesterone, and estradiol concentrations. Group B was used to evaluate fertility, and groups C and D were added to clarify the role of male rats in the fertility of nephrotic female rats. The results showed a persistent proteinuria in nephrotic rats; the estrous cycle of nephrotic animals was d isrupted. The LH and estradiol concentrations were significantly low at all time points evaluated, whereas no significant changes were noted in FSH or progesterone values. In addition, fertility and litter size were diminishe d in nephrotic female rats. Interestingly, the presence of a male rat or it s urine resulted in a positive influence on serum estradiol concentrations of nephrotic female rats. These data indicate that experimental chronic nep hrosis results in a pituitary-ovarian dysfunction that is characterized by low LH concentration, hypoestrogenism, failure of the hormonal feedback con trol, and diminution of fertility. In addition, they show the positive effe ct of a male rat on the fertility of a nephrotic female, which strongly sug gests the participation of pheromones.