Heterogeneity of rat FSH by chromatofocusing: studies on serum FSH, hormone released in vitro and metabolic clearance rates of its various forms.
Heterogeneity of rat FSH by chromatofocusing: studies on serum FSH, hormone released in vitro and metabolic clearance rates of its various forms.
复制标题
色谱聚焦法测定大鼠 FSH 的异质性：血清 FSH、体外释放激素及其各种形式代谢清除率的研究。
作者：
W. Blum;D. Gupta
大鼠垂体FSH分级色谱聚焦pH 6和3之间。分离了10种组分，其表观等电点在3.1和5.1之间。垂体FSH和FSH在体外分泌的四分之一的垂体腺在促性腺激素释放激素（GnRH）的存在和不存在的比较研究显示，类似的模式的带电物种的细胞内和释放FSH。虽然促性腺激素释放激素增加FSH分泌约四倍，没有影响带电物种的模式进行了观察。利用排阻层析和层析聚焦技术，将垂体FSH与免疫亲和层析提取的血清FSH进行比较。结果表明，血清FSH的分子大小较大，相对转移到更多的酸性成分。本文测定了用聚焦层析法分离的8种FSH组分在成年雄性大鼠体内的代谢清除率。半衰期从13分钟到数小时不等。等电点下降与代谢清除率下降之间存在相关性。这些发现表明，所有垂体FSH成分都以相似的速率分泌到循环中，并且酸性较高的FSH成分似乎含有增加的唾液酸，具有更长的循环半衰期，并且在血清中含量更丰富。结论：唾液酸化可能参与调节血清FSH水平。
Rat pituitary FSH was fractionated by chromatofocusing between pH 6 and 3. Ten components were resolved having apparent isoelectric points between 3.1 and 5.1. A comparative study of pituitary FSH and FSH secreted in vitro by quartered pituitary glands in the presence and in the absence of gonadotrophin-releasing hormone (GnRH) revealed similar patterns of charged species of intracellular and released FSH. Although GnRH increased FSH secretion about fourfold, no influence on the pattern of charged species was observed. Utilizing exclusion chromatography and chromatofocusing, pituitary FSH was compared to serum FSH which had been extracted by immuno-affinity chromatography. The results demonstrate for serum FSH a larger molecular size and a relative shift to more acidic components. Metabolic clearance rates of eight FSH components separated by chromatofocusing were measured in adult male rats. Half-lives varied between 13 min and several hours. A correlation existed between decrease of isoelectric points and decrease of metabolic clearance rates. These findings suggest that all hypophysial FSH components are secreted into the circulation at similar rates and the more acidic FSH components which appear to contain increased sialic acid, have a longer circulatory half-life and are more abundant in serum. It is concluded that sialylation may be involved in modulating serum FSH levels.