Regional Distribution of Prostaglandins D2, E2, and F2α and Related Enzymes in Postmortem Human Brain

Abstract

The presence of prostaglandins D₂, E₂, and F_2α was demonstrated and their contents measured in various regions of postmortem human brain, pineal body, and pituitary by using specific radioimmunoassays and gas chromatography-mass spectrometry. The three prostaglandins were widely distributed in similar concentrations ranging from several hundred pg/g wet weight to about 40 ng/g wet weight. Prostaglandins D₂ and E₂ showed consistent and similar regional distributions in all six brains tested; amounts were high in pineal body, pituitary, olfactory bulb, and hypothalamus. On the other hand, prostaglandin F_2α was distributed more evenly. Prosta- glandin D synthetase and prostaglandin E synthetase activities were found in cerebrum homogenate from a single subject and were recovered from the 100,000 ×g supernatant. The presence of 1 mM glutathione, reduced form, markedly stimulated the activity of prostaglandin E synthetase, but did not affect prostaglandin D synthetase activity. Activity of 15-hydroxyprostaglandin dehydrogenase was found in the cerebrum homogenate and was partially purified. This enzyme required NADP as a cofactor and copurified with prostaglandin E 9-ketoreductase.