Ultrastructural Localization of Prostaglandin Endoperoxide Synthase (Cyclooxygenase) to Isolated, Purified Fractions of Guinea Pig Peritoneal Macrophage and Line 10 Hepatocarcinoma Cell Lipid Bodies

摘要

Subcellular fractions of purified cytoplasmic, nonmembrane-bound lipid bodies were prepared from 3H-arachidonic acid-labeled guinea pig peritoneal macrophages and line 10 hepatocarcinoma cells. These fractions, which contained 3H-arachidonyl lipids, were shown to be devoid of contaminating cellular membranes by electron microscopy, and to contain prostaglandin endoperoxide (PGH) synthase by postembedding immunogold electron microscopy. These findings support a proposed role for these lipid-rich organelles in the generation of eicosanoids by oxidative metabolism of arachidonate in the cyclooxygenase pathway of inflammatory and neoplastic cells.