Schoots A F, Meijer R C, Denucé J M
Dev Biol. 1983 Nov;100(1):59-63. doi: 10.1016/0012-1606(83)90200-2.
Enveloped medaka embryos and denuded zebrafish embryos were exposed to agents that are known to modify the activity of dopaminergic systems. Precocious emergence of medaka embryos was found in the presence of pimozide, salsolinol, and alpha-methyl-rho-tyrosine, whereas delayed hatching occurred with bromocriptine and apomorphine. Moreover, the hatching rate in the light period of medaka eggs, exposed to a 12-hr light/12-hr dark cycle, is significantly higher than in the dark period. Precocious hatching enzyme secretion from denuded zebrafish embryos is caused by salsolinol, whereas dopamine has an opposite effect. At the same time it turned out that in controls hatching enzyme release from denuded zebrafish embryos is well correlated with hatching of enveloped zebrafish embryos. These results do not support the hypothesis proposed by several authors that hatching enzyme is solely mechanically released, but suggest a controlling influence of dopamine receptors, probably located in the developing central nervous system. Assuming a stimulating effect of prolactin on teleostean hatching enzyme secretion, the present data indicate that hypothalamic-hypophyseal tracts are functional at the time of hatching.
将有包膜的青鳉胚胎和去膜的斑马鱼胚胎暴露于已知可改变多巴胺能系统活性的物质中。在存在匹莫齐特、salsolinol和α-甲基-ρ-酪氨酸的情况下，发现青鳉胚胎出现早熟孵化，而用溴隐亭和阿扑吗啡处理则出现孵化延迟。此外，暴露于12小时光照/12小时黑暗周期的青鳉卵在光照期的孵化率显著高于黑暗期。salsolinol可导致去膜斑马鱼胚胎早熟孵化酶分泌，而多巴胺则有相反作用。同时发现，在对照组中，去膜斑马鱼胚胎的孵化酶释放与有包膜斑马鱼胚胎的孵化密切相关。这些结果不支持几位作者提出的孵化酶仅通过机械方式释放的假说，而是表明多巴胺受体可能位于发育中的中枢神经系统，对孵化有控制作用。假设催乳素对硬骨鱼类孵化酶分泌有刺激作用，目前的数据表明下丘脑-垂体束在孵化时发挥功能。
