An indirect action of dopamine on the rat fundus strip mediated by 5-hydroxytryptamine

Abstract

Dopamine in a concentration of 10−7 molar produces a contraction of the rat stomach fundus preparation. This effect is blocked by the 5-HT antagonist methysergide. Repeated exposure to dopamine results in tachyphylaxis, but the sensitivity to dopamine can be restored by incubating the tissue with 5-HT. The results are interpreted as indicating that dopamine releases 5-HT.