THE EFFECTS OF PROSTAGLANDINS ON GUINEA‐PIG ISOLATED INTESTINE AND THEIR POSSIBLE CONTRIBUTION TO MUSCLE ACTIVITY AND TONE

Abstract

Prostaglandins F1α and F2α caused contraction of the longitudinal muscle of both guinea‐pig isolated ileum and colon, apparently by acting directly on the muscle and on cholinergic nerves. They had little effect on ileal circular muscle. Prostaglandins E1 and E2 caused contraction of the longitudinal muscle of guinea‐pig isolated colon, apparently by acting directly on the muscle and on excitatory nerves which are non‐cholinergic. Prostaglandin E1 seems more effective than E2 in stimulating these nerves. It seems likely that prostaglandin release in vitro maintains the tone of the longitudinal muscle of guinea‐pig colon, whereas release of a prostaglandin E compound inhibits circular muscle tone. 1975 British Pharmacological Society