ENDOCRINE CONTROL OF FETAL ADRENAL MEDULLA CATECHOLAMINE

这项研究的目的是调查选定的 激素和肾上腺皮质在调节肾上腺髓质 绵羊胎儿的儿茶酚胺分泌。 为了研究激素的作用， 妊娠100-115天、120-135天和135-145天的胎儿，新生儿 在1-5天和5-10日龄，并将成年母羊进行研究。 肾上腺 将髓质分散成单细胞，接种并培养在 克-汉二氏培养基。 催乳素、血管紧张素II、精氨酸 加压素和皮质醇对三者合成和释放的影响 将测定儿茶酚胺-多巴胺、去甲肾上腺素和肾上腺素 在孵育1、3、6、9、12和24小时。 放射酶测定将 用于测量三种儿茶酚胺的浓度。 将建立剂量-反应关系。 的响应性 肾上腺髓质对每种激素的反应将在以下动物中进行比较： 不同的年龄组。 为了研究肾上腺皮质在 调节髓质的儿茶酚胺分泌，皮质的能力， 释放儿茶酚胺刺激因子将使用肾上腺 妊娠135至140天的胎儿组织。 首先，皮层细胞 将测试孵育培养基中的儿茶酚胺刺激活性， 肾上腺髓质细胞 第二，这种分泌模式 将通过测试培养基来确定儿茶酚胺刺激因子 从培养肾上腺皮质细胞的时间长达48 小时 第三，增加释放这种儿茶酚胺， 刺激因子从皮质细胞的促肾上腺皮质激素和存在 将测试肾上腺髓质细胞。 对于后一项研究，胎儿 肾上腺皮质细胞将与髓质细胞重组， 共孵育。 皮质因子的释放将与 形态变化或结构特化， 相差显微镜和电子显微镜。 第四，隔离本 肾上腺皮质儿茶酚胺刺激因子将使用 生化分离程序。 最后，大脑皮层的存在 年轻胎儿、新生儿和成人肾上腺皮质中的因子 追究 这些研究将提供基本的了解， 内分泌因子参与肾上腺髓质的调节 胎儿在发育过程中分泌的儿茶酚胺。 他们将 评估肾上腺皮质在控制中的作用的意义 肾上腺髓质的分泌功能。

The purpose of the proposed study is to investigate the role of selected hormones and the adrenal cortex in the regulation of adrenal medullary catecholamine secretion in the ovine fetus. To study the hormone effects, fetuses of 100-115 days, 120-135 days, and 135-145 days gestation, newborns at 1-5 days and 5-10 days, and the adult ewe will be studied. The adrenal medulla will be dispersed into single cells, plated and cultured in Krebs-Henseleit medium. The effects of prolactin, angiotensin II, arginine vasopressin and cortisol on the synthesis and release of the three catecholamines-dopamine, norepinephrine, and epinephrine-will be determined at 1, 3, 6, 9, 12 and 24 hours of incubation. A radioenzymatic assay will be used to measure the concentrations of the three catecholamines. Dose-response relationships will be established. The responsiveness of the adrenal medulla to each of the hormones will be compared among animals of different age groups. To study the role of the adrenal cortex in regulating medullary catecholamine secretion, the ability of the cortex to release a catecholamine stimulatory factor will be determined using adrenal tissues from fetuses of 135 to 140 days gestation. First, cortical cell incubation medium will be tested for catecholamine stimulatory activity in adrenal medullary cells. Second, the secretory pattern of this catecholamine stimulatory factor will be determined by testing the medium obtained from incubating adrenal cortical cells for periods up to 48 hours. Third, the augmentation of release of this catecholamine stimulatory factor from the cortical cells by ACTH and by the presence of adrenal medullary cells will be tested. For the latter study, fetal adrenal cortical cells will be recombined with medullary cells and coincubated. The release of the cortical factor will be correlated with morphologic changes or structural specialization as examined under the phase-contrast and electron microscope. Fourth, the isolation of this adrenal cortical catecholamine stimulatory factor will be performed using biochemical separation procedures. Finally, the presence of this cortical factor in the adrenal cortex of younger fetuses, newborns and adults will be investigated. These studies will provide the basic understanding of the endocrine factors involved in the regulation of adrenal medullary catecholamine secretion in the fetus during development. They will evaluate the significance of the role of the adrenal cortex in the control of adrenal medullary secretory function in the near-term fetus.