Stabilizing effects of cholesterol on changes in membrane permeability and potential induced in red blood cells by lysolecithin.
Effects of cholesterol on permeability of K+ ion and on change in membrane potential induced by lysolecithin were studied. Cholesterol inhibited K+ release from rabbit red blood cells treated with lysolecithin (1.25 micrograms/ml), 3.3 X 10(-6) M of cholesterol being the optimum concentration for blocking K+ release. Changes in membrane potential, monitored by changes in intensity of fluorescence of cyanine dye, were induced by lysolecithin and inhibited by cholesterol. The inhibitory action on both K+ permeability and membrane potential varied with the cholesterol concentration. The observed effects are thought to be due to membrane-stabilizing activities such as decreasing membrane fluidity and hardening the membrane at the fluid-phase transition temperature. These properties of cholesterol may have significance in relation to transformed cells (tumor cells, lymphomed cells).
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects*; D002784:Cholesterol / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects*; D004912:Erythrocytes / Q000187:drug effects*; D006461:Hemolysis / Q000187:drug effects; D008244:Lysophosphatidylcholines / Q000037:antagonists & inhibitors*; D008564:Membrane Potentials / Q000187:drug effects*; D011188:Potassium / Q000378:metabolism; D011817:Rabbits
D008244:Lysophosphatidylcholines; D002784:Cholesterol; D011188:Potassium