HORMONAL CONTROL OF GROWTH

荷尔蒙对生长的控制

• 批准号: 3312737
• 负责人: CHARLES S NICOLL
• 金额: $ 9.84万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-04-01 至 1987-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3312737
• 关键词: embryo /fetus; embryo /fetus transplantation; growth factor; hormone regulation /control mechanism; insulin; mature animal; newborn animals; radioassay; thyroid hormones; thyroidectomy; tissue /cell culture

A significant number of human neonates are smaller than normal at birth. These infants are less healthy and have a higher mortality than neonates of normal weight. Information on hormones that regulate growth of fetuses is sparse and contradictory, and virtually nothing is known about possible hormonal effects on the growth of mammalian embryos in utero. Meaningful information on these subjects may allow the incidence of human fetal growth retardation to be reduced. We will investigate the hormones that are required for growth and differentiation of rats during the embryonic, fetal and neonatal periods using new techniques that we have developed. One of these involves transplanting whole early embryos, or fetal paws under the kidney capsule of juvenile or adult syngeneic rats. At this site transplanted tissue grows well and differentiates normally. Our previous work indicates that growth of fetal rat tissues requires insulin (I) and somatomedins (SM). We will investigate when embryonic tissue develops a dependence on these hormones by transplanting embryos into hosts that are either diabetic (D) or hypophysectomized (HX). The latter are SM deficient. We have also shown that sometime after birth the tissues of the rat become dependent on thyroid hormones (TH), and growth hormone (GH) for growth. We will investigate when this dependence emerges by transplanting xiphoid cartilage from neonatal rats under the kidney capsule of month-old host rats which are intact, HX or thyroidectomized (TX). A divergence in the growth curves of the transplants in the TX and HX hosts will indicate when they became dependent on GH (or SM) and TH, respectively. The direct effects in vivo of growth promoting hormones (I, SM, TH and GH) on growth of transplanted tissue from embryos, fetuses and neonates will be investigated using a new infusion procedure. The tissues are transplanted under the capsule of both kidneys of host rats which are either HX or D. The artery to one kidney is cannulated and hormone solutions are infused into the cannulated renal artery via an osmotic minipump. Thus the transplants on the infused kidney are exposed to direct effects of the hormone while the transplants on the contralateral kidney are unaffected. We will also test the direct growth promoting effects of hormones in juvenile and adult rats that are HX or D by infusing solutions into the right femoral artery. Growth of the tissues on the right leg is compared to that in the left (uninfused) leg. The possibility that infusing GH into one leg of HX rats will cause production of SM will also be investigated.

相当数量的人类新生儿在出生时比正常人小。 这些婴儿的健康状况较差，死亡率高于新生儿。 正常体重。 关于调节胎儿生长的激素的信息是 稀疏且矛盾，几乎不知道任何可能的情况 激素对子宫内哺乳动物胚胎生长的影响。 有意义 关于这些主题的信息可能允许人类胎儿生长的发生率 减速要减少。 我们将研究荷尔蒙 在胚胎期、胎儿期和哺乳期， 和新生儿期使用我们开发的新技术。 之一 这些包括移植整个早期胚胎，或胎儿爪子下， 幼年或成年同系大鼠的肾被膜。 本站上 移植组织生长良好，分化正常。 我们以前的 研究表明，胎鼠组织的生长需要胰岛素（I）， 生长调节素（SM）。 我们将研究胚胎组织何时发育成 通过将胚胎移植到 糖尿病（D）或垂体切除（HX）。 后者是SM 不足 我们还表明，出生后的某个时候， 大鼠变得依赖于甲状腺激素（TH）和生长激素（GH）， 增长 我们将通过移植来研究这种依赖性何时出现 月龄大鼠肾被膜下剑突软骨 完整、HX或甲状腺切除（TX）的宿主大鼠。 一个分歧， TX和HX宿主中移植物的生长曲线将表明 当它们分别依赖于GH（或SM）和TH时。 直接 生长促进激素（I、SM、TH和GH）对生长的体内作用 胚胎、胎儿和新生儿的移植组织 使用新的输注程序进行研究。 组织被移植到 在HX和D. 一个肾脏的动脉被插管，并注入激素溶液 通过渗透性微型泵注入肾动脉 因此 在输注的肾脏上的移植暴露于 而对侧肾脏的移植不受影响。 我们还将测试激素的直接生长促进作用， 幼年和成年大鼠是HX或D通过注入溶液到 右股动脉 比较右腿组织的生长情况 左为左为右，右为右。 将生长激素注入 还将研究HX大鼠的一条腿是否会引起SM的产生。