Early life stress reduces renal function in male rats

Abstract

The first aim of this study was to investigate whether exposure to early life stress, maternal separation (MS), renders sex‐specific effects on basal creatinine clearance (Ccreat) and proteinuria (UprotV). Previously, we reported that male rats exposed to MS display enhanced sensitivity to chronic ang II infusion compared to normally‐reared control (C) male rats. Thus, the second aim was to determine whether female MS rats also display enhanced sensitivity to a chronic infusion of ang II. MS was performed in male and female WKY rats 3 hrs/day from day 2 to 14 of life. Plasma and 24 hr urine samples were collected at baseline (12 wks old). Ccreat was reduced in male MS (n=5) compared to C (n=7) rats (1.32±0.10 vs. 0.99±0.09 ml/min, respectively, p<0.05). Similar Ccreat was observed in female MS and C rats (n=6). UprotV was significantly higher in males than females (p<0.05), however it was similar between MS and C rats. Female MS and C rats were implanted with ang II osmotic mini‐pumps (65 ng/min, sc) and blood pressure (MAP) monitored by telemetry for 2 wks. MAP was similar in female MS and C rats at baseline. Female MS rats displayed greater sensitivity to ang II‐induced hypertension (153±5 vs. 137±5 mmHg, respectively, n=3–4, p<0.05). These studies suggest that early life stress reduces GFR in male but not female rats, while enhanced blood pressure sensitivity to ang II is evident in both sexes.