ZINC AND THE SYNTHESIS OF ZINC BINDING PROTEINS

这个项目的总体目标是研究 锌结合蛋白金属硫蛋白与哺乳动物锌的关系 新陈代谢。重点放在整合蛋白质的诱导 对小肠对锌的吸收，对肠道锌的调节 肝、肾、肠中锌的浓度和细胞内锌代谢 和前列腺癌。由该项目支持的研究表明， 金属硫蛋白是由饮食和肠外锌以及 糖皮质激素。这是通过改变可翻译的 金属硫蛋白mRNA池，很可能是由于改变的结果 金属硫蛋白基因的表达。部分纯化的大鼠肝脏 利用金属硫蛋白mRNA制备双链插入用基因 转化到pBR325质粒中，并转化到大肠杆菌宿主。A基因 分离到一个含有金属硫蛋白的序列。这个克隆的cdna，当 NICK被翻译成掺入32P-dCTP，作为探针用于定量 金属硫蛋白在肝、肾、肠和前列腺组织中的表达。这个 改变膳食锌供应、内毒素诱导金属硫蛋白mRNA的表达 和白细胞内源性介质给药，禁食，急性 感染、肠外营养和链脲佐菌素诱导的糖尿病AS 以及胰高血糖素和糖皮质激素的管理是变量，将 接受检查。金属硫蛋白mRNA在妊娠和妊娠中的表达 将对胎儿、新生儿和母婴进行哺乳检查。其效果 母体缺锌、饮酒和内毒素暴露的关系 将对胎儿金属硫蛋白mRNA进行评估。适用于所有实验 金属硫蛋白结合的锌和铜以及总金属硫蛋白将 作为变量进行测量，并与mRNA水平相关。肾损伤的诱导 金属硫蛋白在锌和铜肾处理中的合成 将检查隔离的、灌流的肾脏。人体对锌的吸收 分离的血管灌流肠道将与金属硫蛋白有关 在各种条件下的合成都会改变吸收。这个 肝脏锌代谢与金属硫蛋白诱导的关系 将检测果糖1，6-二磷酸酶活性。

The overall goal of this project is to investigate the synthesis of the zinc binding protein, metallothionein, as it relates to mammalian zinc metabolism. Emphasis is placed on integrating the induction of the protein to zinc absorption by the small intestine, regulation of the p lasma zinc concentration and intracellular zinc metabolism in liver, kidney, intestine and prostate. Research supported by this project has demonstrated that metallothionein is induced by dietary and parenteral zinc as well as glucocorticoids. This is effected by a change in the translatable metallothionein mRNA pool, most likely as the result of altered metallothionein gene experssion. A partially purified rat liver metallothionein mRNA was used to prepare double stranded cDNA for insertion into a pBR325 plasmid and transfection of an E. coli host. A cDNA containing metallothionein sequencee was isolated. This cloned cDNA, when nick translated to incorporate 32P-dCTP, is used as a probe to quantitate metallothionein mRNA levels in liver kidney, intestine and prostate. The induction of metallothionein mRNA by altered dietary zinc supply, endotoxin and leukocytic endogenous mediator administration, fasting, acute infection, parenteral alimentation and streptozotocin-induced diabetes as well as glucagon and glucocorticoids administration are variables that will be examined. The metallothionein mRNA levels during gestation and lactation will be examined in both the fetus, neonate and dam. The effect of maternal zinc deficiency, alcohol consumption and endotoxin exposure on fetal metallothionein mRNA will be evaluated. For all experiments metallothionein-bound zinc and copper and total metallothionein will be measured as variables and related to mRNA levels. The induction of renal metallothionein synthesis on the renal handling of zinc and copper by the isolated, perfused kidney will be examined. The absorption of zinc by the isolated vascularly perfused intestine will be related to metallothionein synthesis under a variety of conditions that will alter absorption. The relationship of liver zinc metabolism and metallothionein induction to fructose 1,6-bisphosphatase activity will be examined.