Figure 4. VSMC IP3R1 deletion attenuates peripheral vascular constriction induced by HF.

(A) Myography traces recorded in cannulated mesenteric arteries during stepwise incremental increases in pressure (namely 80, 100, and 120 mmHg) at a constant temperature of 37°C in regular buffer (green background) and a Ca²⁺-free buffer (light blue background). For clarity, only the sham curve for IP3R1^fl/fl mice is shown (not significantly different from the responses in IP3R1^VSMC–/– mice). (B) Individual myogenic tone values are shown as the mean ± SEM. n = 5/group. *P < 0.05 versus IP3R1^fl/fl mice, by 2-tailed Student’s t test. Of note, the difference in the myogenic contractile response (*P < 0.05) cannot be attributed to modifications in wall thickness (see Supplemental Figure 6).