Apamin distinguishes two types of relaxation mediated by enteric nerves in the guinea-pig gastrointestinal tract

摘要: Eight smooth muscle preparations from the stomach, small intestine and large of guinea-pig were used to compare apamin's actions in reducing effectiveness transmission enteric inhibitory nerves responses agonists alpha, beta-methylene ATP, VIP isoprenaline. The effects apamin on reflexes ileum colon also evaluated. Apamin had little or no effect isoprenaline any region, but consistently substantially reduced ATP. Responses stimulation neurons by antrum circular muscle, longitudinal taenia coli distal it was ineffective fundus proximal muscle. It caused a reduction relaxation ileal reflexly distension, did not modify similar descending reflex colon. is concluded that can be distinguish two types non-noradrenergic gastrointestinal Furthermore, neither nor ATP sole transmitter chemical released throughout tract.