Addition-order dependent modulation of the sensitivity of rabbit erythrocyte membrane to bee venom phospholipase A2 by oleic acid, lysophosphatidyl choline and albumin.
The addition of exogenous oleic acid to erythrocyte membranes induces a characteristic membrane crenation and sensitises the cells to the lytic action of phospholipase A2 enzymes. Both effects are extremely sensitive to inhibition by endogenous lysophosphatidyl choline (LPC), but the strength of inhibition depends of the order in which the reagents are added to the cells. These responses are further enhanced when the reagents are extracted from the cell membranes by treatment with albumin. Thus the inhibitory action of LPC added before oleic acid increases when the reagents have been extracted but that of LPC added after oleic acid decreases after extraction. The results are discussed in terms of the stimulation of PLA2 activity by enhanced membrane curvature.
Ahmad
T
T
Department of Cell Biology, University of Glasgow, U.K.
Mezna
M
M
Chettibi
S
S
Lawrence
A J
AJ
D000418:Albumins / Q000494:pharmacology; D000818:Animals; D001514:Bee Venoms / Q000201:enzymology*; D002463:Cell Membrane Permeability; D004305:Dose-Response Relationship, Drug; D004910:Erythrocyte Membrane / Q000187:drug effects*; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology; D010741:Phospholipases A / Q000633:toxicity*; D054467:Phospholipases A2; D011817:Rabbits
D000418:Albumins; D001514:Bee Venoms; D008244:Lysophosphatidylcholines; D009829:Oleic Acids; D019301:Oleic Acid; D010741:Phospholipases A; D054467:Phospholipases A2