OXYGEN AND THE DEVELOPMENT OF THE AVIAN EMBRYO

鸟类胚胎发育受氧气供应的影响， 孵化 我们建议研究02可用性对以下方面的影响： 组织毛细作用; 2）孵化后的行为和生长。 在 此外，3）02可用性的变化影响的机制 将研究胚胎生长。 1)脑毛细血管密度， 心脏、骨骼肌和绒毛膜尿囊将通过 形态测定和体积技术在孵育过程中，使用 来自“生长加速”的组织（由60%培养箱02生产 浓度）和“生长延迟”（通过涂覆部分的 蛋壳）以及“对照”（在21%O2中孵育）小鸡。 2)行为 将使用巴甫洛夫条件反射范式进行研究， 无条件刺激 全身生长将由每天 在孵化后一个月内称重小鸡。 器官的生长将 通过分析湿重和干重以及DNA和 蛋白 3)02可用性变化影响的机制 胚胎生长将通过测量血浆浓度来研究 合成代谢激素在实验和控制胚胎，血浆 葡萄糖、游离脂肪酸和氨基酸氮的浓度，以及 通过对已知分泌合成代谢的器官进行形态学检查， 物质. 组织中超氧化物歧化酶，乳酸， 丙酮酸、NAD和NADH将被测量作为组织02的指示剂 张力 组织氧张力将直接在培养的 胚胎 组织ATP、ADP和AMP浓度将在 大脑、听力和骨骼肌。 我们将尝试将增长率 （根据重量、DNA和蛋白质的变化判断）和毛细血管密度。 每个组织（心脏、脑骨骼肌和绒毛尿囊） 02张力或其指标（超氧化物歧化酶浓度， 乳酸/丙酮酸和NAD/NADH 0与合成代谢的血浆浓度 激素和脂质，并具有分泌活动的形态学证据 在甲状腺、脑垂体和胰岛细胞中。

Avian embryonic development is influenced by oxygen availability during incubation. We propose to study ahe effects of 02 availability upon: 1) tissue capillarity, and 2) behavior and growth after hatching. In addition, 3) the mechanisms by which changes in 02 availability affect embryonic growth will be investigated. 1) Capillary density in brain, heart, skeletal muscle, and the chorioallantois will be measured by morphometric and volumetric technics during the course of incubation, using tissue from "growth-accelerated" (produced by 60% incubator 02 concentration) and "growth-retarded" (produced by coating part of the eggshell) as well as "contarol" (incubated in 21% 02) chicks. 2) Behavior will be studied using Pavlovian conditioning paradigms with heat as the unconditioned stimulus. Whole body growth will be determined by daily weighing of the chicks for one month after hatching. Growth of organs will be measured by analyses of wet and dry weights, and analyses for DNA and protein. 3) The mechanisms by which changes in 02 availability affect embryonic growth will be investigated by measuring the plasma concentration of anabolic hormones in experimental and control embryos, the plasma concentrations of glucose, free fatty acids, and amino acid nitrogen, and by morphologic examination of organs which are knwn to secret anabolic substances. The tissue concentrations of superoxide dismutase, lactate, pyruvate, NAD and NADH will be measured as indicators of tissue 02 tension. Tissue oxygen tension will be measured directly in cultured embryos. Tissue ATP, ADP and AMP concentrations will be measured in brain, hear, and skeletal muscle. We will attempt to correlate growth rate (judged by changes in weight, DNA and protein) and capillary density of each tissue (heart, brain skeletal muscle and chorioallantois) with tissue 02 tension or its indicators (superoxide dismutase concentration, lactate/pyruvate and NAD/NADH0 with the plasma concentrations of anabolic hormones and lipids, and with morphological evidence of secretory activity in the cells of the thyroid, pituitary and pancreatic islets.