“Corticosterone, an inhibitor of OCT subtype 1, 2 and 3 reduced acetylcholine in a concentration‐dependent manner … an IC50 value of 2 μM. Substrates of OCT subtype 1, 2 and 3 (amiloride, cimetidine, guanidine , noradrenaline, verapamil) inhibited acetylcholine release , whereas carnitine, a substrate of subtype OCTN2, exerted no effect.”