代谢
铝通过口服或吸入暴露的吸收情况很差，并且基本上不会通过皮肤吸收。铝的生物利用度受到铝化合物的影响，以及饮食成分的存在，这些成分可以与铝形成复合物，增强或抑制其吸收。铝在血液中与各种配体结合并分布到每个器官，其中在骨骼和肺组织中浓度最高。在生物体中，铝被认为存在四种不同的形式：作为自由离子，作为低分子量复合物，作为物理结合的大分子复合物，以及作为共价结合的大分子复合物。吸收的铝主要通过尿液排出，其次是在胆汁中，而未吸收的铝则通过粪便排出。摄入一定量的硝酸盐和亚硝酸盐是人类氮循环的正常部分。在适当的条件下，硝酸盐可以在胃肠系统中转化为亚硝酸盐，显著增强硝酸盐的毒性。硝酸盐的主要代谢途径是转化为亚硝酸盐，然后转化为氨。亚硝酸盐、硝酸盐及其代谢物通过尿液排出。
Aluminum is poorly absorbed following either oral or inhalation exposure and is essentially not absorbed dermally. The bioavailability of aluminum is strongly influenced by the aluminum compound and the presence of dietary constituents which can complex with aluminum and enhance or inhibit its absorption. Aluminum binds to various ligands in the blood and distributes to every organ, with highest concentrations found in bone and lung tissues. In living organisms, aluminum is believed to exist in four different forms: as free ions, as low-molecular-weight complexes, as physically bound macromolecular complexes, and as covalently bound macromolecular complexes. Absorbed aluminum is excreted principally in the urine and, to a lesser extent, in the bile, while unabsorbed aluminum is excreted in the faeces. Intake of some amount of nitrates and nitrites is a normal part of the nitrogen cycle in humans. In vivo conversion of nitrates to nitrites can occur in the gastrointestional tract under the right conditions, significantly enhancing nitrates' toxic potency. The major metabolic pathway for nitrate is conversion to nitrite, and then to ammonia. Nitrites, nitrates, and their metabolites are excreted in the urine. (L1137, L739)
来源:Toxin and Toxin Target Database (T3DB)
