Fig 3.

Angiotensin II-mediated vasoconstriction increases later in life in females and is attenuated by smooth muscle cell-specific MR deletion (SMC-MR-KO) in males and females. A and B: second and third order mesenteric resistance vessels (MRVs) were isolated from 3-, 12-, and 18-mo-old MR-intact and SMC-MR-KO male (A) and female (B) mice. Vessel tension induced by ANG II (1 × 10⁻⁷ M) was determined by wire myography; n = 3–4/group. C–F: total RNA was extracted from MRVs and quantitative RT/PCR was performed to quantify angiotensin II type 1b receptor and mineralocorticoid receptor mRNA expression; n = 3–8/group. Differences were assessed via two-way ANOVA with Tukey post hoc testing where appropriate. MR, mineralocorticoid receptor; ANG II, angiotensin II; AT₁R, angiotensin II type 1 receptor. Data are means ± SE; *P < 0.05, **P < 0.01, ***P < 0.001.