プロトボルフィリンのヒト赤血球膜に対する影響

抄録

Effect of protoporphyrin on the membrane of human erythrocytes was investigated by measuring the shape change and osmotic hemolysis. Protoporphyrin induced crenation on human erythrocyte membrane dose-dependently and the maximal effect was observed within 5 min of incubation under the conditions used. The effect on hypotonic hemolysis of the cells was biphasic ; protection of hemolysis at lower concentrations and stimulation at higher concentrations. The crenation induced by protoporphyrin was reversed to normal biconcave shape by washing the cells with albumin solution, but not with isotonic saline. Furthermore, the protoporphyrin-induced crenation was antagonized by the action of phospholipase C which by itself converted normal biconcave erythrocytes into invaginated cells due to the hydrolysis of phosphatidylcholine in the membrane. These membrane-acting behaviors of protoporphyrin are similar to those of lysolecithin and phospholipase A₂, known reagents causing disturbance of membrane lipid bilayer. Thus, protoporphyrin induces the rearrangement of lipid bilayer in erythrocyte membrane which might cause disturbance of the membrane-related functions of the cells.