Dual challenge for glomerular damage in mice: uninephrectomy and repetitive pregnancies

We examined the effects of unilateral nephrectomy (UNx) and repetitive pregnancies (RP) on glomerular damage and blood pressure in mice. Four groups of 10 female mice, 7 weeks old, underwent sham nephrectomy (SV) alone, sham nephrectomy and six pregnancies (SP), right nephrectomy alone (NV) and right nephrectomy followed by six repetitive pregnancies (NP). UNx resulted in a significant elevation of serum creatinine up to 11 weeks. In all animals pregnancy was associated with a temporary decrease in serum creatinine except at termination of the 6th pregnancy in group NP. UNx and RP did not result in an increase in protein excretion. UNx in both virgin and pregnant mice resulted in blood pressure elevation without any renal histological abnormalities by the end of the 6th pregnancy. We conclude that at least up to the end of the 3rd pregnancy, gestation was associated with augmentation in function of a single kidney. This effect was lost by the end of the 6th pregnancy. Multiple repetitive pregnancies in uninephrectomized animals entailed renal functional deterioration and a rise in blood pressure without renal histological abnormalities on light microscopy.