Fig. 6.

Na⁺/H⁺ exchanger isoform 3 (NHE3) and Na⁺-K⁺-2Cl⁻ cotransporter (NKCC2) expression. A: immunoblot analysis of cortical NHE3 expression with quantification of sham-operated control (SOC) mice, orchiectomized (ORCH) mice that received placebo pellets that released no hormone (ORCH + P), and mice that had a controlled-release pellet (60-day release) containing 1.5 mg/pellet of testosterone implanted subcutaneously at the time of ORCH (ORCH + T). ORCH + P mice had significantly less NHE3 expression than SOC or ORCH + T mice. B: immunohistochemistry examining NHE3 immunolabel in the proximal convoluted tubule (PCT; top), cortical proximal straight tubule (PST; middle), and PST outer medulla (OM; bottom) in SOC (left), ORCH + P (middle), and ORCH + T (right) mice. NHE3 immunolabel intensity was less in cortical proximal tubule segments in ORCH + P mice than SOC or ORCH + T mice. NHE3 immunolabel was not detectably different across groups in the PST OM. C: quantitative immunohistochemistry showing that ORCH + P mice had significantly less NHE3 expression in the PCT and cortical PST than did SOC or ORCH + T mice. There was no significant difference in NHE3 expression across groups in the PST OM. D: immunoblot analysis of cortical NKCC2 expression with quantification of SOC, ORCH + P, and ORCH + T mice. ORCH + P mice had significantly greater NKCC2 protein expression than SOC or ORCH + T mice. E: immunohistochemistry examining NKCC2 immunolabel in the cortex (CTX; top) and OM (bottom) in SOC (left), ORCH + P (middle), and ORCH + T (right) mice. NKCC2 immunolabel intensity was greater throughout the thick ascending limb (TAL) in ORCH + P mice than SOC or ORCH + T mice. n = 6 SOC mice, 6 ORCH + P mice, and 5 ORCH + T mice. NS, not significant.