代谢
硫酸钡化合物通过摄入和吸入被吸收,其程度取决于个别化合物。在人体内,大部分的钡存在于骨骼中,而少量存在于肌肉、脂肪、皮肤和结缔组织中。钡在体内不被代谢,但它可能会被运输或结合到复合物或组织中。钡通过尿液和粪便排出。铜主要通过胃肠道吸收,但也可以通过吸入和皮肤吸收。它通过基底外侧膜,可能是通过调节铜转运蛋白,并与血清白蛋白结合运输到肝脏和肾脏。肝脏是铜稳态的关键器官。在肝脏和其他组织中,铜以与金属硫蛋白、氨基酸结合,并与依赖铜的酶相关联的形式储存,然后分配通过胆汁排出或结合到细胞内和细胞外蛋白中。铜通过血浆与血清白蛋白、铜蓝蛋白或低分子量复合物结合输送到外周组织。铜可能会诱导金属硫蛋白和铜蓝蛋白的产生。膜结合的铜转运腺苷三磷酸酶(Cu-ATPase)将铜离子输送到细胞内和细胞外。生理上正常的铜水平通过改变铜的吸收速率和量、分布区域以及排泄来保持恒定。(L277, L279, L214)
Barium compounds are absorbed via ingestion and inhalation, the extent of which depends on the individual compound. In the body, the majority of the barium is found in the bone, while small amounts exists in the muscle, adipose, skin, and connective tissue. Barium is not metabolized in the body, but it may be transported or incorporated into complexes or tissues. Barium is excreted in the urine and faeces. Copper is mainly absorbed through the gastrointestinal tract, but it can also be inhalated and absorbed dermally. It passes through the basolateral membrane, possibly via regulatory copper transporters, and is transported to the liver and kidney bound to serum albumin. The liver is the critical organ for copper homoeostasis. In the liver and other tissues, copper is stored bound to metallothionein, amino acids, and in association with copper-dependent enzymes, then partitioned for excretion through the bile or incorporation into intra- and extracellular proteins. The transport of copper to the peripheral tissues is accomplished through the plasma attached to serum albumin, ceruloplasmin or low-molecular-weight complexes. Copper may induce the production of metallothionein and ceruloplasmin. The membrane-bound copper transporting adenosine triphosphatase (Cu-ATPase) transports copper ions into and out of cells. Physiologically normal levels of copper in the body are held constant by alterations in the rate and amount of copper absorption, compartmental distribution, and excretion. (L277, L279, L214)
来源:Toxin and Toxin Target Database (T3DB)