Histaminergic Transmission in a Frog Vagus Stomach Muscle Preparation

Abstract

1. In certain seasons, vagal stimulation of frog stomach muscle produces contraction or relaxation which is abolished if the muscle is desensitised to histamine by mepyramine or histamine, suggesting the release of histamine.

2. The above contraction or relaxation may require other antagonists such as atropine, 2-bromolysergic acid diethylamide or acetylsalicylic in addition to mepyramine, suggesting the release of acetylcholine, 5-hydroxytryptamine and polypeptides in addition to histamine.