MOBILIZATION OF ARACHIDONIC-ACID IN HUMAN PLATELETS KINETICS AND CA2+ DEPENDENCY
MOBILIZATION OF ARACHIDONIC-ACID IN HUMAN PLATELETS KINETICS AND CA2+ DEPENDENCY
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DOI：
10.1016/0005-2760(77)90196-5
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发表时间：
1977-01-01
期刊：
影响因子：
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通讯作者：
DEYKIN, D
中科院分区：
文献类型：
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作者：
RITTENHOUSESIMMONS, S;RUSSELL, FA;DEYKIN, D
还研究了凝血酶对[3 H]花生四烯酸和[14 C]甘油掺入血小板磷脂的影响。[3 H]花生四烯酸在暴露于来自磷脂酰胆碱和磷脂酰肌醇的凝血酶的预标记血小板中释放，并在烷-1-烯基-酰基-甘油磷酸乙醇胺中出现越来越多的酯化。最大转移发生在5 U/ml的凝血酶和15分钟的孵育，并依赖于Ca 2+的存在，但血清素最大释放0.04 U/ml的凝血酶。在与凝血酶孵育期间，血小板表面没有发生缩醛磷脂（与二酰基乙醇胺相反）的优先暴露。[3 H]花生四烯酸到alk-1-enyl-acyl-glycerophosphohoethanolamine的刺激掺入并不伴随着刺激[14 C]甘油摄取到这种磷脂。而不是刺激从头合成，血小板的扰动激活磷脂酶A2的活动，导致周转的花生四烯酸在血小板血浆酶原。这种周转可以帮助提供底物，用于通过环氧合酶和脂氧化酶转化为生物活性代谢物。
The effect of thrombin on the incorporation of [3H]arachidonic acid and [14C]glycerol into platelet phosphatides was also studied. [3H]Arachidonic acid was released in pre-labeled platelets exposed to thrombin from phosphatidylcholine and phosphatidylinositol and appeared increasingly esterified in alk-1-enyl-acyl-glycerophosphoethanolamine. Maximum transfer occurred with 5 U/ml of thrombin and 15 min of incubation and was dependent upon the presence of Ca2+, but serotonin was maximally released with 0.04 U/ml of thrombin. No preferential exposure of plasmalogen (as opposed to diacyl) ethanolamine at the platelet surface occurred during incubation with thrombin. The stimulated incorporation of [3H]arachidonic acid into alk-1-enyl-acyl-glycerophosphoethanolamine was not accompanied by a stimulation of [14C]glycerol uptake into this phosphatide. Rather than stimulating de novo synthesis, perturbation of the platelet activates a phospholipase A2 activity leading to turnover of arachidonic acid in platelet plasmalogen. Such turnover may help provide substrate for conversion by cyclooxygenase and lipoxydase to biologically active metabolites.