Diabetes and pregnancy in Wistar rats: renal effects for mothers in the postpartum period

In this study, diabetes mellitus (DM) was induced in Wistar rats during pregnancy and maintained in the postpartum period (PP) and we evaluated systolic blood pressure (SBP), glomerular filtration rate (GFR) and renal immunohistochemical and morphometric studies from different groups: G1 (non-pregnant control rats), G2 (non-pregnant diabetic rats), G3 (control mothers) and G4 (diabetic mothers). We found that there were no differences in relation to SBP, but there was a tendency for reduction in GFR from G4 compared with the other groups (G). There was increased total kidney weight/body weight ratio of G4 compared with other G. There were increase in glomerular tuft area in G3 and G4 compared with G1 and G2. G2 and G4 showed even higher percentage of cortical collagen. G3 showed increased glomerular proliferating cells compared with G1 and G2, while in G4 this number was smaller than G3. Cell proliferation was higher in the tubulointerstitial (TBI) compartment from G4. Glomerular and TBI α-smooth muscle actin expression was increased in G4 compared with other G. The glomerular p-p38 expression showed a pattern similar to proliferation cell nuclear antigen, with a reduction of p-p38 in G4 relative to other G. The immunoreactivity of p-JNK was higher in both the glomeruli and TBI compartment in G4 compared with G1, G2 and G3. The DM induced during pregnancy and maintained in the PP resulted in renal structural and functional changes to mothers. In addition, altered mitogen-activated protein kinase expression in association with these changes may play an important role in renal damage observed in the present investigation.