Fig. 4.

Effects of β-NAD and adenosine 5-diphosphate-ribose (ADPR) on PDGFRα⁺ cells and SMCs. A and D: current-clamp recordings from a PDGFRα⁺ cell in the dialyzed whole cell configuration (I = 0). β-NAD (1 mM) and ADPR (10 μM) elicited fast transient hyperpolarization, with peaks at about −80 mV. Hyperpolarization responses were blocked by MRS 2500 (1 μM). B and E: summary of inhibition of β-NAD and ADPR responses by MRS 2500 (n = 5 and 6, respectively). *P = 0.0141 and 0.0020, respectively (by paired t-test). Hyperpolarization responses in B and E are tabulated as area under response curves (mV·min). C and F: current-clamp recordings from a SMC in the perforated-patch whole cell configuration (I = 0). β-NAD (1 mM) and ADPR (10 μM) had no effect on RMPs of SMCs.