(A) Mean internal capillary diameter at pericyte somata during exposure to endothelin-1 (ET-1) (10 nM), normalized to the diameter measured in the absence of ET-1, in acute cortical slices of wild-type or ANO1-KO mice. (B) TMEM16A KO reduced the average ET-1–evoked pericyte contraction during the last 5 minutes of the experiment (Ano KO, n = 27; Wild-type, n = 19). (C) Mean internal capillary diameter at pericyte somata during exposure to 92.5 mM extracellular potassium ([K+]o), normalized to the diameter measured in the presence of 2.5 mM [K+]o in acute rat cortical slices. (D) Raising [K+]o evokes pericyte contraction, and this is not reduced by Ani9 (2 μM). Points indicate individual pericytes from 5 rats per condition (–Ani9: n = 5; +Ani9: n = 6). (B and D) Unpaired 2-tailed Student’s t test.