海湾扇贝幼虫变态过程中体内神经递质含量的变化

采用生化方法测定了不同发育阶段及人工诱导后海湾扇贝 (Argopectenirradians)幼虫体内去甲肾上腺素 (NE)、多巴胺 (DA)和 5 羟色胺 ( 5 HT)含量的变化。结果表明 ,海湾扇贝幼虫体内去甲肾上腺素含量在变态前后没有明显变化 ,变态前为 2 35 2pg/mg湿重 ,变态后为2 770pg/mg湿重。多巴胺和 5 羟色胺含量在变态前 (第 1 3天 )急剧增加 ,比第 1 2天的幼虫分别增加了 2 .8倍和 4.7倍 ,变态后急剧下降 ,变态后幼苗比第 1 3天的幼虫分别降低了 2 5 .1倍和 1 6.4倍。海湾扇贝幼虫体内DA∶NE比值和 5 HT∶NE比值在变态前后变化剧烈。DA∶NE比值和 5 HT∶NE比值在变态前 (第 1 3天 )急剧增加 ,比第 1 2天的幼虫增加了 3.0倍 (DA∶NE)和 5 .0倍 ( 5 HT∶NE) ;变态后急剧降低 ,变态后幼苗比第 1 3天的幼虫降低了 2 9.8倍 (DA∶NE)和 1 9.5倍 ( 5 HT∶NE)。海湾扇贝幼虫经氯化钾和氯化钙诱导 2 4h后 ,体内去甲肾上腺素、多巴胺和 5 羟色胺以及DA∶NE比值和 5 HT∶NE比值均有所降低。本实验的结果表明 ,多巴胺和 5 羟色胺可能启动了海湾扇贝幼虫的变态过程。

THE CHANGES OF NEUROTRANSMITTER CONTENT DURING METAMORPHOSIS OF BAY SCALLOP ARGOPECTEN IRRADIANS LARVAE

The changes of norepinephrine( NE) , dopamine( DA) and 5-hydroxytryptamine( 5-HT) in larvae of bay scallop Argopecten irradians at different development stages and after induced by KCl and CaCl₂ have been studied. The results show that NE levels in the corresponding larva and spat groups do not change significantly, with 2352( pg/mg WW) ( before metamorphosis, 13d) and 2770( pg/mg WW) ( spats ). DA and 5-HT levels are low in young larvae, then increase with larvae developing. DA and 5-HT levels increase drastically just before metamorphosis( 13d) , which increase 2.8 and 4.7 times respectively compared to 12-day larvae. After metamorphosis, DA and 5-HT levels decrease drastically, which in spats following metamorphosis decrease25.1 and 16.4 times respectively compared to 13-day larvae. The DA : NE ratio and 5-HT : NE ratio also change drastically among 12-day larvae, 13-day larvae and spats. The DA : NE ratio and 5-HT:NE ratio increase drastically just before metamorphosis, which increase 3.0 and 5.0 times, respectively, and then decrease drastically after metamorphosis. The DA : NE ratio and 5-HT : NE ratio in spats decrease 29.8 and 19.5 times compared to 13-day larvae. The NE, DA and 5-HT levels and DA : NE ratio, 5-HT : NE ratio decrease after induced by KCl and CaCl₂. The results suggest that DA and 5-HT maybe trigger the metamorphosis process of bay scallop A. irradians.