Effect of VDR inactivation on renin expression and plasma Ang II production. (a) Renin mRNA expression in the kidney. Kidney total RNAs were isolated from wild-type (+/+) and VDR–/– (–/–) mice and analyzed by Northern blot. The same membrane was sequentially hybridized with mouse renin and 36B4 cDNA probes. Each lane represents an individual animal. (b) Quantitative results of the Northern blot analyses shown in a. Values represent the ratio of renin mRNA to 36B4 mRNA. *P < 0.001 vs. wild-type mice. (c) Immunohistochemical staining of the kidney cortex from wild-type and VDR–/– mice with anti-renin antiserum. Arrows indicate the afferent glomerular arterioles in the JG region. Scale bar, 25 μm. (d) Plasma Ang II concentrations in wild-type and VDR–/– mice. *P < 0.001 vs. wild-type mice; n = 15 in each group. (e) Liver angiotensinogen mRNA expression in wild-type and VDR–/– mice, determined by Northern blot. The membrane was sequentially hybridized with mouse angiotensinogen and 36B4 cDNA probes. Each lane represents an individual mouse.