Renal disease in gravid animal models.

Micropuncture studies in the rat have indicated that in the short term, the superimposition of pregnancy on an experimentally induced, advanced, autologous phase glomerulonephritis (GN) does not lead to any worsening of the functional or morphological changes characteristic of this disease. Indeed, pregnant rats with GN exhibit a tendency toward higher GFR and plasma flow rate than do virgin rats with this disease. In chronic studies to investigate the long-term effects on kidney function of pregnancy, normal rats undergoing five closely spaced pregnancies and lactations exhibit glomerular hemodynamics, 24-hour protein excretions, and morphology similar to those of age-matched virgins. When repetitive pregnancies are superimposed on rats with the long-term hyperfiltration stimuli of uninephrectomy plus high dietary protein feeding, no worsening of the proteinuria occurs in comparison to virgin rats subjected to the same degree of renal ablation plus high protein. Although filtration and plasma flow rates are lower in these repetitively pregnant rats as compared with virgin rats, amino acid infusion revealed substantial renal reserve in the repetitively pregnant rats. These studies show that gestational hyperfiltration does not, in and of itself, provide an adverse stimulus to the maternal kidney.