INHIBITION OF PHOSPHOLIPID-FACILITATED CALCIUM TRANSPORT BY CENTRAL NERVOUS SYSTEM-ACTING DRUGS

Narcotic analgesics effectively inhibit the binding of Ca2+ to phospholipids in vitro. Morphine and nalorphine also inhibit the Ca2+ transported by phospholipids obtained from guinea pig brain subcellular fractions. The inhibition of Ca2+ transported was related to ionization of the drug and was compared with the analgesic potency of the narcotic drugs. About 69 per cent of morphine-14C was bound to phosphatidic acid and this binding was inhibited by divalent ions (3-29 per cent). Various CNS-acting drugs were also effective in inhibiting the transport of Ca2+ ions by phosphatidic acid. It is postulated that an alteration in the binding of ions to phospholipids within the neuronal membrane may be involved in the pharmacological action of CNS-acting drugs. © 1969.