ZINC METABOLISM IN ISOLATED LIVER CELLS

我们的目标是研究锌的调节机制。 以及肝脏对铜的代谢。这是通过使用主要的、 大鼠肝实质细胞的单层培养。研究表明， 证明糖皮质激素增加了细胞内的积聚 锌的再分布和金属硫蛋白的表达增强 (MT)基因。胰高血糖素增强了这一过程。铜的积累是 受肾上腺素刺激。糖皮质激素增加铜蓝蛋白(CP) 肾上腺素增加细胞外流时细胞的合成和分泌 铜作为铜蓝蛋白。我们现在可以来看看 机制更详细，并将它们放在功能上下文中。在……里面 下一阶段，将进一步评估铜和锌的吸收动力学。 通过总细胞保留，快速累积/快速保留 交换了细胞池和外排交换。这些参数将是 比较胎鼠、去肾上腺的年轻成年大鼠、老年大鼠的细胞 成年大鼠和链脲佐菌素诱导的糖尿病大鼠。的影响 地塞米松、肾上腺素、胰高血糖素和加压素及其组合 这些以及LEM和IL-1对细胞铜和锌摄取的影响 铜蓝蛋白合成-分泌和MT合成-降解 检查过了。放线菌素D和放线菌素对蛋白质合成的抑制作用 放线菌亚胺和蛋白质分泌与衣霉素和亮肽素将 用于评价MT和CP的相关机制。肝细胞毒素， 最初的溴苯和叔丁基氢过氧化氢和铁诱导的脂质 将评估过氧化对摄取动力学、荷尔蒙的影响 反应性和细胞金属硫蛋白含量和合成， 铜蓝蛋白的合成和分泌，细胞内谷胱甘肽(GSH和 GSSG)、脂质过氧化、GSH过氧化物酶和GSH还原酶，H202 生产，葡萄糖生产和~3H-脯氨酸掺入胶原。 用~(32)P-cDNA法测定MT和CP基因表达水平的变化 杂交和Northern杂交。细胞将缺铜 或通过改变培养液中的铜和锌含量而缺锌。之后 评估缺陷的标准已经满足，对 缺乏激素刺激的细胞和抵抗细胞的能力 手柄中的细胞毒素将进行检测。铜、锌的保护作用 补充、硒、α-生育酚、13-顺式维甲酸和特定激素 将对地塞米松进行评估。

Our goal is to investigate the mechanisms involved in regulation of zinc and copper metabolism by the liver. This is approached using primary, monolayer cultures of rat liver parenchymal cells. Research has demonstrated that glucocorticoids increase the intracellular accumulation and redistribution of zinc and enhanced expression of the metallothionein (MT) gene. Glucagon augments this process. Copper accumulation is stimulated by epinephrine. Glucocorticoids increase ceruloplasmin (Cp) synthesis and secretion while epinephrine increases the efflux of cellular copper as ceruloplasmin. We are now in a position to look at the mechanisms in more detail and place them within a functional context. In the next phase, copper and zinc uptake kinetics will be further evaluated via total cellular retention, retention of the fast accumulated/rapidly exchanged cellular pool and efflux exchange. These parameters will be compared in cells from fetal rats, adrenalectomized young adult rats, old adult rats and streptozotocin-induced diabetic rats. The influences of dexamethasone, epinephrine, glucagon and vasopressin and combinations of these as well as LEM and interleukin-1 on cellular copper and zinc uptake and ceruloplasmin synthesis-secretion and MT synthesis-degradation will be examined. Inhibitions of protein synthesis with actinomycin D and cycloheximide and protein secretion with tunicamycin and leupeptin will be used to evaluate the mechanisms relating to MT and Cp. Liver cell toxins, initially bromobenzene and t-butyl hydroperoxide and Fe-induced lipid peroxidation will be evaluated for an effect on uptake kinetics, hormonal responsiveness and cellular metallothionein content and synthesis, ceruloplasmin synthesis and secretion, intracellular glutathione (GSH and GSSG), lipid peroxidation, GSH peroxidase and GSH reductase, H202 production, glucose production and 3H-proline incorporation into collagen. Changes in MT mRNA and Cp mRNA levels will be measured by 32P-cDNA hybridization and northern blotting. Cells will be made copper deficient or zinc deficient by altering the Cu and Zn content of the media. After criteria to evaluate deficiency have been satisfied, the response of deficient cells to hormonal stimulation and the ability of defient cells to handle the cell toxins will be tested. The protective effect of Cu and Zn repletion, Se, Alpha-tocophenol, 13-cis-retinoic acid and specific hormones e.g. dexamethasone will be evaluated.