Classification of beta-blocking agents by their inhibitory effects on phospholipase activity.

The inhibitory effects of beta-blocking agents against the action of phospholipase (PLase) were investigated. Using micelles of dimyristoyl (-)-alpha-phosphatidylcholine (DMPC) as a substrate, myristic acid (MA) released from DMPC by PLase A2 was determined by gas chromatography. Beta-Blocking agents were divided into 4 groups depending on their inhibitory effects on PLase. Their inhibitory effects on PLase could be due to their displacing ability with Ca++ on membrane phospholipids, since Ca++ is an essential factor for the activation of PLase.