DEVELOPMENT OF TISSUE THERMOGENESIS IN NEWBORN ANIMALS

该项目的总体目标有三个方面。 第一、 棕色脂肪组织（BAT）发育的表征 胎儿和新生儿的新陈代谢将继续进行。 二是 甲状腺激素影响BAT功能和代谢的机制 胎儿和新生儿将得到澄清，最后，BAT的作用， 在新生儿饮食诱导产热（DIT）中的作用将是 评估。 我们的具体目标是：1）描述 BAT线粒体嘌呤核苷酸结合，儿茶酚胺受体，和 胎兔和新生兔腺苷酸环化酶活性。 2)确定 甲状腺状态变化对BAT细胞呼吸、脂解 脂肪生成，线粒体嘌呤核苷酸结合，儿茶酚胺 受体和腺苷酸环化酶活性。 3)到 确定一顿饭的影响和长期摄入高浓度的 脂肪或碳水化合物饮食对体内耗氧量，BAT温度， BAT组成，BAT细胞呼吸，脂解，脂肪生成， 线粒体嘌呤核苷酸结合，儿茶酚胺受体和腺苷酸 环化酶活性。 4)为了确定 长期摄入高脂肪或碳水化合物饮食对身体成分的影响 和新生兔子的生长。 5)为了确定BAT介导的DIT是否可以 可以通过饮食、进食频率或阻断剂来操纵， 新生兔子 使用的方法将包括测量体内氧气 消耗，BAT温度，体外细胞呼吸，脂解， 脂肪生成，儿茶酚胺受体，细胞酶，甲状腺激素， 放射免疫分析和身体成分。 这些研究将增加我们对新生儿产热的理解， 可能会带来新的治疗方法， 最大限度地利用能源， 包括早产儿和足月儿。

The overall objectives of this project are threefold. First, characterization of the development of brown adipose tissue (BAT) metabolism in the fetus and newborn will be continued. Second, the mechanism whereby thyroid hormones influence BAT function and metabolism in the fetus and newborn will be clarified, and finally, the role that BAT plays in diet induced thermogenesis (DIT) in the newborn will be evaluated. Our specific aims are: 1) To characterize the maturation of BAT mitochondrial purine nucleotide binding, catecholamine receptors, and adenyl cyclase activity in fetal and newborn rabbits. 2) To determine the effect of changes in thyroid status on BAT cellular respiration, lipolysis, lipogenesis, mithochondrial purine nucleotide binding, catecholamine receptors and adenyl cyclase activity in the newborn rabbit. 3) To determine the effect of a single meal and the chronic ingestion of a high fat or carbohydrate diet on in vivo oxygen consumption, BAT temperature, BAT composition, BAT cellular respiration, lipolysis, lipogenesis, mitochondrial purine nucleotide binding, catecholamine receptors and adenyl cyclase activity in the newborn rabbit. 4) To determine the effect of the chronic ingestion of a high fat or carbohydrate diet on body composition and growth in the newborn rabbit. 5) To determine if BAT mediated DIT can be manipulated by either diet, feeding frequency or blocking agents in the newborn rabbit. The methods used will include the measurement of in vivo oxygen consumption, BAT temperature, in vitro cellular respiration, lipolysis, lipogenesis, catecholamine receptors, cellular enzymes, thyroid hormones by RIA, and body composition. These studies will increase our understanding of neonatal thermogenesis and possibly lead to new therapeutic approaches that will minimize energy expenditure for thermogenesis and maximize energy utilization for growth in both premature and full term infants.