水通道蛋白4在大鼠脑垂体中的表达

目的：研究水通道蛋白4(AQP4)及其mRNA在脑垂体中的表达，探讨其在脑垂体激素分泌过程中的作用。方法：应用免疫组织化学和原位杂交技术，观察成年Wistar大鼠脑垂体中AQP4及其mRNA的正常分布。结果：AQP4及其mRNA在成年大鼠神经垂体的垂体细胞上表达呈阳性，分布在毛细血管窦周围的垂体细胞表达尤为强烈。腺垂体的所有细胞均有AQP4的表达，胞质中AQP4 mRNA表达呈阳性。中间叶所有细胞AQP4及其mRNA的表达呈弱阳性，其中滤泡星形细胞表达较内分泌细胞强烈。结论：AQP4广泛分布于脑垂体的各种组织细胞表面，可能在垂体激素的正常分泌过程中起重要的调节作用。

Expression of aquaporin 4 in adult rat pituitary gland

Objective: To explore the expression of aquaporin-4 (AQP4) and AQP4 mRNA in adult rat pituitary gland and to discuss its function in the process of pituitary hormone secretion. Methods: The localization of AQP4 and AQP4 mRNA in pituitary gland of adult rats were examined by in situ hybridization histochemistry and immunohistochemistry technique. Results: Strong positive signals were observed in the pituicyte of adult rat neurohypophysis, especially around the sinusoid. All the cells of the adenohypophysis, including acidophil, basophil, chromophobe cells and folliculo-stellate cells, were AQP4 positive on the membrane and AQP4 mRNA positive in the plasma and nucleus. The heavily stained cells surrounding sinusoid may be the folliculo-stellate cells, and other positive cells may be endocrine cells. All the cells of the intermediate lobe of the hypophysis were positive with AQP4 protein and AQP4 mRNA. The positive expression degree of folliculo-stellate cells were stronger than that of the endocrine cells. Conclusion: AQP4 is widely expressed on the membrane of the putuitary cells, and it may play an important role in the process of the putuitary hormone secretion.