Chatelain A, Cheong H S
Laboratoire de Physiologie Animale, UFR des Sciences Exactes et Naturelles, Université de Picardie, Amiens, France.
Acta Endocrinol (Copenh). 1987 Oct;116(2):179-85. doi: 10.1530/acta.0.1160179.
The responsiveness of perifused adrenal glands removed from rats at various stages of gestation to similar immunological quantities (2 ng) of 'big' approximately equal to 30,000 mol wt), 'intermediate' (congruent to 13,000 mol wt) and 'little' (approximately equal to 4500 mol wt) ACTH isolated by gel filtration chromatography from an acid extract of pituitary glands of 21 day-old rat foetuses was determined. This immunological quantity failed to induce a maximal response of the foetal adrenals. Corticosterone was determined in the effluent perifusion by a radiocompetition assay. On days 17 and 19 of gestation, intermediate and little ACTH had, on a weight basis, the same corticosteroidogenic activity, but on day 21 the little was more potent than the intermediate form. The corticosterone release by these two forms of ACTH was log-dose dependent. The biological activity of big ACTH was very low on day 17, slightly increased until day 21 but remained significantly lower than that of intermediate and little forms. Big ACTH added to little ACTH in the perifusion medium did not modify the corticosteroidogenic activity of little ACTH on days 17, 19 and 21 of gestation.
测定了从处于不同妊娠阶段的大鼠身上取出的经灌流肾上腺，对通过凝胶过滤色谱法从21日龄大鼠胎儿垂体腺酸提取物中分离出的相似免疫量（2纳克）的“大”（约30,000道尔顿分子量）、“中”（约13,000道尔顿分子量）和“小”（约4500道尔顿分子量）促肾上腺皮质激素（ACTH）的反应性。该免疫量未能诱导胎儿肾上腺产生最大反应。通过放射竞争测定法测定灌流流出物中的皮质酮。在妊娠第17天和第19天，按重量计算，中等和小分子量的ACTH具有相同的皮质类固醇生成活性，但在第21天，小分子量的ACTH比中等分子量的更有效。这两种形式的ACTH释放皮质酮呈对数剂量依赖性。大分子量ACTH的生物活性在第17天非常低，直到第21天略有增加，但仍显著低于中等和小分子量形式。在妊娠第17天、第19天和第21天，在灌流培养基中添加到大分子量ACTH中的小分子量ACTH并没有改变小分子量ACTH的皮质类固醇生成活性。
