The contribution of prostaglandins in the muscle of human isolated small intestine to neurogenic responses.
1. In stris cut parallel to the longitudinal or circular muscle, indomethacin (2--10 microgram/ml) usually lowered the tone, thus probably accounting for the reduction of nerve-mediated relaxations to electrical field stimulation. 2. In longitudinal muscle strips, indomethacin enhanced contractions which occurred during electrical stimulation, probably because tone fell, but antagonized after-contractions. By contrast, in the circular muscle indomethacin reduced initial contractions but enhanced after-contractions. 3. Prostaglandin E2 counteracted all of the effects of indomethacin in the longitudinal muscle and most of those in the circular muscle; prostaglandin F2alpha restored circular muscle tone. 4. The results suggest that prostaglandins affect the muscle directly and contribute to the regulation of tone. They may also mediate non-cholinergic contraction in longitudinal muscle and suppress contractility in the circular muscle.
D004558:Electric Stimulation; D006801:Humans; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007213:Indomethacin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D007583:Jejunum / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011453:Prostaglandins / Q000494:pharmacology*
D011453:Prostaglandins; D007213:Indomethacin