Fig. 4.
In vivo ENaC activity: net natriuretic response to ENaC blockade with benzamil (0.7 mg/kg). Each rat had vehicle and benzamil injected intravenously on consecutive days. Five virgin, seven late-pregnant, and four late-pregnant rats with eplerenone (EPL; 100 mg/kg) were studied. Urine was collected 0–3 h and 3–8 h following injection for determination of sodium excretion (UNaV). Data from the 0–3-h period are shown here; there were no significant differences among groups in the natriuretic response 3–8 h after ENaC blockade. Net UNaV was calculated as UNaV following benzamil minus UNaV following vehicle. A one-way ANOVA was performed. Values are expressed as means ± SE; *P < 0.05 vs. Virgin.