Effect of luminal benzamil (1 μm) on Na reabsorption, JNa, in the CCD of male (A) and female (B) mice. Benzamil significantly inhibited JNa in male and female mice (male control 72.6 ± 8.6 vs. benzamil 43.8 ± 8.7, *P < 0.05, n = 6; female control 67.8 ± 17.9 vs. benzamil 41.1 ± 18.0, *P < 0.05, n = 6). Extended line connects the means ± SE for the 2 experimental periods.