Marion J, Pappius H M, Wolfe L S
Biochim Biophys Acta. 1979 May 25;573(2):229-37. doi: 10.1016/0005-2760(79)90056-0.
To determine if the arachidonic acid which is released post-mortem in rat cerebral cortex is directly available for the in vitro synthesis of prostaglandin F2 alpha, cerebral cortex slices or homogenates were incubated in the presence of [2H8]arachidonic acid. The deuterium to protium ratios in the prostaglandin F2 alpha were compared to those in the free arachidonic acid and other lipids of the tissue after 5 and 60 min of incubation. In the slice, the prostaglandin F2 alpha reached maximum labelling before any of the lipids examined except for a pool of rapidly labelled free arachidonic acid located at the damaged surfaces of the tissue. The prostaglandin F2 alpha recovered in the medium after 60 min of incubation had a deuterium to protium ratio twice that of the prostaglandin F2 alpha found in the tissue. Norepinephrine doubled the labelling of the prostaglandin produced by the slice. The labelling of the prostaglandin F2 alpha in homogenates was 10 times higher than in tissue slices and the deuterium to protium ratio of the total free arachidonic acid was similar to that of prostaglandin F2 alpha. The results indicate that exogenous and endogenous arachidonic acid do not mix appreciably in the intact slice and that the prostaglandin synthetase is present on the damaged surface as well as the intact interior of the slice.
为了确定大鼠大脑皮层死后释放的花生四烯酸是否可直接用于体外合成前列腺素F2α，将大脑皮层切片或匀浆在[2H8]花生四烯酸存在下孵育。孵育5分钟和60分钟后，比较前列腺素F2α中的氘与氢的比率与组织中游离花生四烯酸和其他脂质中的比率。在切片中，除了位于组织受损表面的一组快速标记的游离花生四烯酸外，前列腺素F2α在任何检测的脂质之前达到最大标记。孵育60分钟后在培养基中回收的前列腺素F2α的氘与氢的比率是组织中发现的前列腺素F2α的两倍。去甲肾上腺素使切片产生的前列腺素的标记增加了一倍。匀浆中前列腺素F2α的标记比组织切片高10倍，总游离花生四烯酸的氘与氢的比率与前列腺素F2α相似。结果表明，外源性和内源性花生四烯酸在完整切片中没有明显混合，并且前列腺素合成酶存在于切片的受损表面以及完整内部。
