ZINC AND THE SYNTHESIS OF ZINC BINDING PROTEINS

本项目的总体目标是研究合成的 与哺乳动物锌相关的锌结合蛋白，金属硫蛋白 新陈代谢. 重点放在整合蛋白质的诱导 小肠对锌的吸收，血浆锌的调节 肝、肾、肠组织中锌浓度和细胞内锌代谢 和前列腺 该项目支持的研究表明， 金属硫蛋白是由饮食和胃肠外锌诱导的， 糖皮质激素 这是受可译事物的变化影响的 金属硫蛋白mRNA库，最有可能是由于改变 金属硫蛋白基因表达。 部分纯化的大鼠肝脏 金属硫蛋白mRNA用于制备用于插入的双链cDNA pBR 325质粒中，并转染E. coli宿主。 的cdna 含有金属硫蛋白序列。 这个克隆的cDNA，当 切口平移以掺入32P-dCTP，用作探针以定量 肝、肾、肠和前列腺中金属硫蛋白mRNA水平。 的 锌、内毒素对金属硫蛋白mRNA诱导作用 和白细胞内源性介质给药，禁食，急性 感染、胃肠外营养和链脲佐菌素诱导糖尿病， 以及胰高血糖素和糖皮质激素的给药是变量， 接受检查。 妊娠期金属硫蛋白mRNA水平的变化， 将检查胎仔、新生儿和母鼠的泌乳情况。 效果 母亲缺锌、饮酒和内毒素暴露对 将评估胎儿金属硫蛋白mRNA。 对于所有实验 金属硫蛋白结合的锌和铜和总金属硫蛋白将是 作为变量测量并与mRNA水平相关。 肾脏的诱导 金属硫蛋白合成对肾脏处理锌和铜的影响 将检查离体灌注的肾脏。 锌的吸收， 离体血管灌注肠与金属硫蛋白有关 在各种条件下的合成将改变吸收。 的 肝锌代谢与金属硫蛋白诱导的关系 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.