PROTECTIVE EFFECTS OF NEUTRAL AMINO-ACIDS AGAINST AMPHIPATHIC DRUG-INDUCED HEMOLYSIS

Some neutral amino acids were compared for their anti-hemolytic effect s with sugars which are well-known colloid-osmotic protectants. The ki netic studies in isotonic suspensions of erythrocytes indicated that t he hemolysis induced by the amphipathic drug chlorpromazine (CPZ) or f lufenamic acid (FA) was retarded by addition of sugars, and the degree of the anti-hemolytic effect increased with increases in molecular si ze. Phenylalanine (Phe), the largest among the amino acids tested, sho wed the greatest inhibitory effect on CPZ-induced hemolysis, but not o n FA-induced hemolysis. This demonstrated that the anti-hemolytic effe cts of amino acids were not the result of colloid-osmotic protection. Hemolytic actions of amino acids were also examined to determine their interaction with the erythrocyte membrane, and the mechanism of their inhibitory effects against amphipathic drug-induced hemolysis was dis cussed.