Fertility diminution in female rats with experimental chronic nephrosis

Chronic aminonucleoside nephrosis in rats is an experimental analogue of human focal segmental glomerulosclerosis. This study was undertaken to define the effects of chronic nephrosis on the pituitary-ovarian axis and on fertility. Chronic nephrosis was induced by puromycin aminonucleoside and followed for 112 days. The estrous cycle was evaluated daily in all rats, whereas biochemical parameters, hormonal concentrations, and fertility were measured on Days 7, 14, 28, 56, 84, and 112 (n = 8). Animals were divided in four experimental groups: A, B, C, and D. Group A was used to determine LH, FSH, 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 disrupted. 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 diminished in nephrotic female rats. Interestingly, the presence of a male rat or its urine resulted in a positive influence on serum estradiol concentrations of nephrotic female rats. These data indicate that experimental chronic nephrosis results in a pituitary-ovarian dysfunction that is characterized by low LH concentration, hypoestrogenism, failure of the hormonal feedback control, and diminution of fertility. In addition, they show the positive effect of a male rat on the fertility of a nephrotic female, which strongly suggests the participation of pheromones.