An in vitro method for assay of hormone or agonist-stimulated lipase activity

An assay for in vitro measurement of hormone or agonist-stimulated lipase activity, using exogenous prostaglandin synthetase as a trap for liberated arachidonic acid is described. Fifteen of twenty-six hormones and agonists previously tested in vivo, were tested in vitro and either stimulated or inhibited release of arachidonic acid parallel to their activity in vivo. Vasopressin stimulated the release of arachidonic acid in a linear, log-dose manner, from 10(-11) M to 10(-5) M.