Wehrenberg W B, Chatelain P, Baird A
Proc Soc Exp Biol Med. 1986 May;182(1):107-11. doi: 10.3181/00379727-182-42317.
The different molecular weight forms of immunoreactive growth hormone (irGH) secreted by the anterior pituitary of rats were evaluated during basal and stimulated secretion in vitro and in vivo. Anterior pituitary cells maintained in a monolayer culture system secreted only a 22,000-Da form of GH based on Sephacryl S-200 column chromatography. This was also true for the irGH secreted in response to growth hormone-releasing factor and prostaglandin E2 stimulation. In contrast, the molecular weight forms of irGH found in plasma under basal conditions included an approximately 90,000-Da form as well as the expected 22,000-Da form. The concentrations of both forms increased following growth hormone-releasing factor stimulation although there was a shift in the ratio of the forms secreted. These results suggest that the larger molecular weight forms of rat GH observed in plasma may be the result of some postsecretory process which occurs in blood and suggests a possible regulatory function for the larger molecular weight forms as it pertains to the bioavailability of GH in vivo.
在体外和体内的基础分泌和刺激分泌过程中，对大鼠垂体前叶分泌的不同分子量形式的免疫反应性生长激素（irGH）进行了评估。基于Sephacryl S - 200柱色谱法，维持在单层培养系统中的垂体前叶细胞仅分泌一种22,000道尔顿形式的生长激素。对于生长激素释放因子和前列腺素E2刺激所分泌的irGH也是如此。相比之下，基础条件下血浆中发现的irGH分子量形式包括一种约90,000道尔顿的形式以及预期的22,000道尔顿形式。生长激素释放因子刺激后，两种形式的浓度均增加，尽管所分泌形式的比例发生了变化。这些结果表明，血浆中观察到的大鼠生长激素较大分子量形式可能是血液中发生的某种分泌后过程的结果，并且表明较大分子量形式可能对生长激素在体内的生物利用度具有调节功能。
