Comparative Study of Prostaglandin Synthesis and Blood Coagulation in the Fish

本文研究了比目鱼、黑鲷、黑石斑鱼和真鲷四种海水鱼洗涤后的血小板悬浮液中标记的高度不饱和脂肪酸合成前列腺素（PG）的情况。用<14>洗涤后的血小板悬液研究[1-^ C] -花生四烯酸（AA），AA主要转化为PGF_<2alpha>2、PGE_2、PGD_2。结果表明，[1-^<14>C]二十碳五烯酸仅在黑石斑鱼血小板中主要转化为PGs，其代谢产物主要为PGE_3和PGD_3。然而，[1-^<14>C]二十二碳六烯酸不是环化成PG在所有物种。用显微镜观察人血小板与鲤鱼、虹鳟、真鲷血小板的聚集行为。人血小板和所有鱼类血小板在离子载体A_、凝血酶和胶原存在下发生聚集<23187>，而在EPA、DHA、PGF_2、PGD_2和ADP存在下不发生聚集。此外，在TXA_2、PGG_2和PGH_2的存在下，鱼的血小板不聚集，而TXA_2、PGG_2和PGH_2可诱导人血小板聚集。鲤鱼凝血细胞悬浮液经胶原蛋白作用后，其上清中含有凝血细胞聚集的诱导物。采用高效液相色谱法从真鲷鳃中提取内源性产物，经紫外吸收光谱和气相色谱-质谱联用技术鉴定为12-羟基二十碳四烯酸、12-羟基二十碳五烯酸和14-羟基二十二碳六烯酸。鲤鱼鳃的内源产物也被鉴定为13-羟基十八碳二烯酸、12-羟基二十碳四烯酸和12-羟基二十碳五烯酸。

Prostaglandin (PG) syntheses from the labelled highly unsaturated fatty acids were investigeted in washed thrombocytes suspensions of four species of marine fish, flounder, black sea bream, black rockfish, and red sea bream. When [1-^<14>C] -arachidonic acid (AA) was investigated with washed thrombocytes suspension, AA was mainly converted to PGF_<2alpha>, PGE_2, PGD_2 in all species. It was suggested that [1-^<14>C] eicosapentaenoic acid was mainly converted into PGs only in black rockfish thrombocytes, and the metabolites were mainly PGE_3 and PGD_3. However, [1-^<14>C] docosahexaenoic acid was not cyclized into PGs in all species. Aggragation behaviors of human platelets and carp, rainbow trout, and red sea bream thrombocytes were studied by an microscopic observation. Human platelets and all fish thrombocytes aggregated in the presence of ionophore A_<23187>, thrombin, and collagen, but did not aggregate in the presence of EPA, DHA, PGF_2, PGD_2 or ADP. Moreover, fish thrombocytes did not aggregate in the presence of TXA_2, PGG_2 , and PGH_2 whose induces the aggragation of human platelets. It was recognized that the inducers of thrombocytes aggregation appeared in the supernatant of carp thrombocytes suspension which aggregated by collagen. However, the structure of the inducers could not be determined.The endogeneous products extracted from the gill of red sea bream were isolated by high-performance liquid chromatography and identified as 12-hydroxyeicosatetraenoic acid, 12-hydroxyeicosapentaenoic acid, and 14-hydroxydocosahexaenoic by ultraviolet absorption spectra and gas chromatography-mass spectrometry. The endogeneous products of carp gill were also identified as 13-hydroxyoctadecadienoic acid, 12-hydroxyeicosatetraenoic acid, and 12-hydroxyeicosapentaenoic acid.