团头鲂尾部神经分泌系统的超微结构及其在人工催产过程中的变化

THE ULTRASTRUCTUREAL CHANGES OF THE CAUDAL NEUROSECRETORY SYSTEM OF MEGALOBRAMA AMBLYCEPHALA DURING THE ARTIFICIALLY INDUCED SPAWNING

在团头鲂尾部神经分泌系统的神经分泌细胞及其轴突中,可观察到三种不同类型的颗粒(即电子致密颗粒、电子致密度较低的颗粒和电子透明颗粒)。细胞质中线粒体、高尔基复合体和粗面内质网都比较发达,游离核糖体较多。在尾垂体的无髓神经纤维之间有时还可观察到桥粒结构。 在性腺Ⅲ期至Ⅵ期,上述的细胞器变化不大,但三种颗粒的数量和分布却有明显的差别。根据团头鲂尾部神经分泌细胞和神经血管复合体超微结构的变化看来,人工催产有促进尾垂体电子致密颗粒中的分泌物向血管内释放的作用。

In the neurosecretory cells of the caudal neurosecretory system of Megalobrama amblycephala, the mitochondria, Golgi complex, rough endoplasmic reticulum and free ribosome are well-developed. The caudal neurosecretory cells and their axons contain three major types of granules, namely electron-lucent granules, electron-dense and less electron-dense granules. The desmosome can be found occasionally between unmyelinated nerve fibres in the urophysis.As the gonads develop from stage Ⅲ to Ⅵ, the changes of organellas are not distinct morphologically. But there are significant differences in number and distribution of three kinds of granules. The ultrastuctural changes of caudal neurosectrory sells and neurohemal regions show that the artificially induced spawning can accelerate releasing the secretory materials of electron-dense granules into the blood capillary.