The effect of bovine serum albumin on the synthesis of prostaglandin and incorporation of [3H]acetate into platelet-activating factor.
The effect of bovine serum albumin on the synthesis of prostaglandin and incorporation of [3H]acetate into platelet-activating factor.
复制标题
牛血清白蛋白对前列腺素合成和[3H]乙酸盐掺入血小板激活因子的影响。
DOI：
10.1016/0003-9861(87)90564-9
复制
发表时间：
1987
影响因子：
3.9
通讯作者：
Taylor,L
中科院分区：
文献类型：
--
作者：
Heinsohn,C;Polgar,P;Fishman,J;Taylor,L
The binding of fatty acids by bovine serum albumin (BSA) is well documented. However, the interaction between the synthesis of prostaglandins (PGs) and the trapping of arachidonate released from cellular lipid stores is not as well understood. In this communication, we relate the trapping of fatty acids to the synthesis of PGs and the incorporation of [3H]acetate into platelet-activating factor (PAF). Our results show that, as determined by radioimmunoassay, BSA inhibits bradykinin (BK) (5 ng/ml) and ionophore A23187 (10 μm)-stimulated synthesis of PGs in human embryo lung fibroblasts (IMR-90) in a concentration-dependent manner. Experiments using prelabel with [3H]arachidonate followed by extraction and thin-layer chromatography show that, in the presence of 2 mg/ml BSA, IMR-90 release essentially only fatty acid following stimulation with bradykinin. Little if any prostaglandin and no endoperoxide are detected. In the same experiment, in absence of BSA, about 70% of the released label is detected as prostaglandin. α-Cyclodextrin, another trapper of fatty acid, inhibits PG synthesis in much the same way. BSA and α-cyclodextrin also inhibit prostacyclin synthesis in endothelial cells derived from the calf pulmonary artery. However, the inhibition of PG synthesis in these cells is not as complete as that in the IMR-90. In contrast to the effect of the trappers on PG synthesis, BSA and α-cyclodextrin are observed to potentiate BK- and ionophore-stimulated incorporation of [3H]acetate into PAF in the endothelial cells. The labeled PAF is not released from the cells in either the presence or absence of the trappers, leading us to conclude that BSA causes an increase in acetate-labeled cellular PAF by trapping released fatty acid.
