Ross B M, Moszczynska A, Kalasinsky K, Kish S J
Human Neurochemical Pathology Laboratory, Clarke Institute of Psychiatry, Toronto, Ontario, Canada.
J Neurochem. 1996 Dec;67(6):2620-3. doi: 10.1046/j.1471-4159.1996.67062620.x.
Dopamine-mediated stimulation of arachidonic acid metabolism, via activation of the phospholipid metabolizing enzyme phospholipase A2 (PLA2), has recently been implicated in dopamine neurotransmitter function. We examined the status of PLA2 in autopsied brain of 10 chronic users of cocaine, a dopamine reuptake inhibitor. PLA2 activity, assayed at pH 8.5 in the presence of Ca2+, was significantly (p < 0.01) decreased by 31% in the putamen of cocaine users (n = 10) compared with that in controls (n = 10), whereas activity was normal in the frontal and occipital cortices, subcortical white matter, and cerebellum. In contrast, calcium-independent PLA2 activity, assayed at pH 7.0, was normal in all brain regions examined. Our finding of altered PLA2 activity restricted to a region of high dopamine receptor density suggests that modulation of PLA2 may be involved in mediating some of the dopamine-related behavioral effects of cocaine and could conceivably contribute to dopamine-related processes in the normal brain.
多巴胺通过激活磷脂代谢酶磷脂酶A2（PLA2）介导花生四烯酸代谢，最近这一过程被认为与多巴胺神经递质功能有关。我们检测了10名可卡因长期使用者（一种多巴胺再摄取抑制剂）尸检大脑中PLA2的状态。在存在Ca2+的情况下，于pH 8.5测定的PLA2活性，与对照组（n = 10）相比，可卡因使用者（n = 10）壳核中的活性显著降低（p < 0.01），降低了31%，而额叶和枕叶皮质、皮质下白质以及小脑中的活性正常。相比之下，在pH 7.0测定的不依赖钙的PLA2活性在所有检测的脑区中均正常。我们发现PLA2活性改变仅限于多巴胺受体密度高的区域，这表明PLA2的调节可能参与介导可卡因的一些与多巴胺相关的行为效应，并且可以想象这可能有助于正常大脑中与多巴胺相关的过程。
