中华鳖脑垂体的显微与超微结构观察

Observation on microstructure and ultrastructure of pituitary in Trionyx sinensis

为了探讨中华鳖脑垂体的组织结构及其季节性变化,采用H.E染色、三色染色和免疫组织化学染色法在光镜下观察中华鳖脑垂体的显微结构,结合电镜对鳖脑垂体进行超微显微观察。结果发现中华鳖脑垂体同样分为神经垂体和腺垂体,但是缺乏中间部。腺垂体包括结节部和远侧部,远侧部可分头叶和尾叶两部分,头叶大于尾叶,神经部很小。腺垂体中的细胞可分为嗜酸性细胞、嗜碱性细胞和嫌色细胞,各类细胞的分布和形态有明显区别。免疫组化染色证明促肾上腺皮质激素(ACTH)细胞密集分布于结节部,在远侧部也有零星分布;促性腺激素(GTH)细胞和生长激素(GH)细胞数量在繁殖季节明显多于冬季。电镜下根据细胞大小、细胞核的形状和胞质中分泌颗粒特征可将腺垂体中的细胞分为GH细胞、ACTH细胞、GTH细胞、催乳激素(LTH)细胞、促甲状腺激素(TSH)细胞和嫌色细胞。在这些细胞间有明显的细胞连接。细胞形态和数量在繁殖季节和冬季有明显变化。

To investigate the histological structure and seasonal variation of the pituitary from Trionyx sinensis, the histological structure of T.sinensis pituitary in September and January was observed under light microscope and electron microscope.HE,PAF-AB-PAS-OG staining and immunohistochemical study were undertaken using different dyes or antisera.From the anatomical point of view,the pituitary of T.sinensis was composed of two lobes：the adenohypophysis and the neurohypophysis.It was functionally linked to the hypothalamus by the pituitary stalk.Adenohypophysis was composed by pars tuberalis and pars distalis,but pars intermedia was absent in the T.sinensis.Pars distalis could be divided into head lobe and tail lobe,and the former was larger than the latter.The neurohypophysis was small and finger-like extending into the pars distalis.Different cells of adenohypophysis were divided into three cells of eosinocyte,basicytes and chromophobe cells.The shape and distribution of those kinds were different obviously.The eosinocytes were mainly located in the central region of pars distalis while the basicyte in the surrounding area,eosinocytes were generally smaller than basicyte and possess a round and sidelined nucleus,the basicyte were bigger and possess a central nucleus; the chromophobe cells and adrenocorticotropic cells were densely distributed in the pars tuberalis and sporadically distributed in the pars distalis.The quantity of somatotrophs and gonadotrophs in breeding season was higher than that in winter while other cells did not change significantly.Under electron microscope,the cells in adenohypophysis were divided into six categories of somatotrophs,gonadotrophs,thyrotrophsprolactin cells, adrenocorticotropic cells,adrenocorticotropic cells and chromophobe cells according to the cell size,shape of nucleolus and secretory granules in the cytoplasm.The quantity of secretory granules in cytoplasm of somatotrophs and gonadotrophs changed significantly in summer and winter.