A, Renal interstitial hydrostatic pressure (RIHP) in uninephrectomized, anesthetized rats during normal or high renal perfusion pressure (RPP) in rats with an intact renal capsule (white bars, n=7), after partial decapsulation (Decap) (black bars, n=6), or after partial decapsulation with RI cortical infusion of cGMP during the experimental period (gray bars, n=7). B, Urine Na+ excretion (UNaV) in response to normal or high RPP in rats under conditions in A (intact capsule, n=8; partial decapsulation, n=7; partial decapsulation with RI cortical infusion of cGMP during the experimental period, n=7). Results are reported per gram (g) kidney weight. C, RI cGMP levels in response to normal or high RPP in rats under conditions in A (intact capsule, n=8; partial decapsulation, n=7; partial decapsulation with RI cortical infusion of cGMP during the experimental period, n=7). Data are shown as mean ± SE. ***P<0.001, **P<0.01 vs own control; †P<0.05 vs intact capsule (ANOVA with Dunnett’s).