Bishai I, Coceani F
Biochim Biophys Acta. 1981 Apr 23;664(1):1-9. doi: 10.1016/0005-2760(81)90023-0.
Transformations of prostaglandin H2 were studied in the whole homogenate and subcellular fractions (microsomes, high-speed supernatant) of the cat brain. Prostaglandin H2 was converted enzymatically to prostaglandin E2, 6-ketoprostaglandin F 1 alpha, and thromboxane B2. While prostaglandin E2 and thromboxane B2 predominated, respectively, in the whole homogenate and the microsomes, 6-ketoprostaglandin F1 alpha was formed in both tissue preparations. Pretreatment of the microsomes with reduced glutathione stimulated the formation of prostaglandin E2 at the expense of 6-ketoprostaglandin F1 alpha and thromboxane B2. Imidazole and 15-hydroperoxyarachidonic acid interfered with the microsome-induced transformations of prostaglandin H2 to thromboxane B2 and 6-ketoprostaglandin F1 alpha, respectively. No prostaglandin D2 was detected even after treatment of the tissue with reduced glutathione. Prostaglandin H2, on the other hand, was converted to prostaglandin F2 alpha, but the yield of this compound in native tissue was equal to, or lower than, that in boiled tissue. We conclude that the feline brain is endowed with several enzymes (prostaglandin E2 isomerase, thromboxane A2 and prostaglandin I2 synthetases) competing for the added endoperoxide. All enzymes were located in the microsomes. No evidence was obtained indicating enzymic reduction of prostaglandin H2 to prostaglandin F2 alpha.
在猫脑的全匀浆和亚细胞组分（微粒体、高速上清液）中研究了前列腺素H2的转化情况。前列腺素H2可通过酶促反应转化为前列腺素E2、6-酮前列腺素F1α和血栓素B2。虽然前列腺素E2和血栓素B2分别在全匀浆和微粒体中占主导，但在两种组织制剂中均形成了6-酮前列腺素F1α。用还原型谷胱甘肽预处理微粒体以6-酮前列腺素F1α和血栓素B2为代价刺激了前列腺素E2的形成。咪唑和15-氢过氧花生四烯酸分别干扰了微粒体诱导的前列腺素H2向血栓素B2和6-酮前列腺素F1α的转化。即使在用还原型谷胱甘肽处理组织后也未检测到前列腺素D2。另一方面，前列腺素H2可转化为前列腺素F2α，但该化合物在天然组织中的产量等于或低于煮沸组织中的产量。我们得出结论，猫脑具有几种竞争添加的内过氧化物的酶（前列腺素E2异构酶、血栓素A2和前列腺素I2合成酶）。所有酶都位于微粒体中。没有证据表明前列腺素H2可酶促还原为前列腺素F2α。
