ENDOCRINE CONTROL OF FETAL ADRENAL MEDULLA CATECHOLAMINE

拟议研究的目的是调查选定的 激素与肾上腺皮质在肾上腺髓质调节中的作用 绵羊胎儿内儿茶酚胺的分泌量。为了研究荷尔蒙的影响， 妊娠100-115天、120-135天和135-145天的胎儿，新生儿 在1-5日龄和5-10日龄时，对成年母羊进行研究。肾上腺 髓质将分散成单个细胞，培养在 Krebs-Henseleit Medium。催乳素、血管紧张素II、精氨酸的作用 加压素和皮质醇对三者合成和释放的影响 儿茶酚胺--多巴胺、去甲肾上腺素和肾上腺素--将被检测 孵化1、3、6、9、12、24小时。放射性酶分析将会 用于测定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影响将在动物之间进行比较 不同的年龄段。目的：研究肾上腺皮质在脑内的作用 调节髓质儿茶酚胺的分泌，皮质的能力 释放一种儿茶酚胺刺激因子将用肾上腺测定 胎龄135-140天的胎儿组织。第一，皮质细胞 将对培养基中儿茶酚胺刺激活性进行测试 肾上腺髓质细胞。第二，这个的秘密模式 儿茶酚胺刺激因子将通过测试培养基来确定 从孵育肾上腺皮质细胞长达48年的时间获得 几个小时。第三，这种儿茶酚胺的释放增加 ACTH和ACTH的存在对皮质细胞的刺激因子 将对肾上腺髓质细胞进行检测。对于后一项研究，胎儿 肾上腺皮质细胞将与骨髓细胞重组，并 共同孵化。皮质因子的释放将与 形态变化或结构特化，如 相差显微镜和电子显微镜。第四，与世隔绝 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、新生儿和成年人的肾上腺皮质中的因子 被调查。这些研究将提供对 肾上腺髓质调节中的内分泌因素 胎儿发育过程中的儿茶酚胺分泌量。他们会 评价肾上腺皮质在控制中的作用 近月胎儿肾上腺髓质分泌功能的变化。

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.