Contractile actions of lysophosphatidic acids with a chemically-defined fatty acyl group on longitudinal muscle from guinea-pig ileum

Abstract

Abstract Various lysophosphatidic acids caused phasic contractions of longitudinal muscle from guinea-pig ileum, followed by rhythmical contractions of lower magnitude. Polyunsaturated lysophosphatidic acids were more potent than saturated lysophosphatidic acids. Among the lysophosphatidic acids tested, linolenoyl-lysophosphatidic acid was the most active, but its activity was about 3–5 times less than that of prostaglandin F2α. Contractile responses to various lysophosphatidic acids, were partially suppressed by tetrodotoxin, atropine and chlorpheniramine. In addition, lysophosphatidic acid-induced contractions were considerably reduced by pretreatment of the muscle with indomethacin.