Fig. 3. Effects of changing extracellular pH on tension produced during continuous exposure of efferent branchial arteries to arginine vasotocin (AVT; 1 nmol l^–1) or KCl (50 mmol l^–1) in Hepes buffer. (A) Raising pH from 7.4 to 8.2 did not significantly affect contraction, whereas AVT and KCl contractions were significantly () decreased when pH was lowered from 8.2 to 7.4. (B) Representative tracings of the KCl responses. Values are means ± s.e.m. (N=4).