Low-molecular-chromium, or nickel-binding substances from liver or milk of animals and their biological functions, especially in relation to detoxication and carcinogenesis of metals.

1.从狗、兔和奶牛的肝脏和初乳中提纯了低分子量(MW：1500)铬结合物质。它们由谷氨酸、甘氨酸和半胱氨酸组成，铬/氨基端残基比例为4：1。与无机铬化合物相比，结合铬的毒性较低，尿排泄率较高。此外，一些纯化物质的体外活性与葡萄糖耐量因子在胰岛素作用方面的活性相当。还从大鼠肝脏中提纯了一种低分子量镍结合物质。在BALB/C3T3细胞集落形成实验中，与其结合的镍显示出比无机镍化合物更低的细胞毒性。该物质在体外结合镍形成镍/分子比为1：1的饱和镍。部分镍被铜或锌等必需元素取代，但不被包括镉、铅和铬在内的非必需元素取代。有机锡化合物三苯基和三丁基锡可抑制胰腺胰岛素的释放、胶原诱导的血小板聚集、白细胞的O_2~-产生和趋化，以及肥大细胞的组胺释放。一种常见的机制似乎是抑制细胞膜上的刺激反应耦合。二丁基锡化合物在体内和体外的抗肿瘤活性可能具有相同的机制。与低分子镍结合物质结合的镍对培养的BALB/C3T3细胞有很强的致癌活性，而无机镍化合物不诱导转化。

1. Low-molecular-weight (MW:1500)-chromium binding substances were purified from the liver and colostrum of dogs, rabbits and cows. They were composed of glutamic acid, glycine and cysteine with a Cr/amino-terminal residue ratio of 4:1. Chromium bound to them showed a lower toxicity and higher rates of urinary excretion than inorganic chromium compounds. Furthermore, some fraction of purified substances showed in vitro activities comparable to those of glucose tolerance factor in relation to insulin action.2. A low-molecular-weight (MW:900)-nickel-binding substance was also purified from the liver of rats. Nickel bound to it showed a lower cytotoxicity in the colony-formation tests using BALB/C 3T3 cells than inorganic nickel compounds. The substance.combined nickel in vitro to form the saturated ones with a Ni/molecule ration of 1:1. Some fractions of nickel were replaced with an essential element such as copper or zinc, but not with a non-essential element inclusing cadmium, lead and chromium.3. Organotin compounds, triphenyl and tributyltins, showed to inhibit insulin release from pancreas, collagen-induced aggregation of platelets, O_2^- production and chemotaxis of leukocytes, and histamine release from mast cells. A common mechanism seemed to be an inhibition of the stimulusresponse coupling in the cell membrane. The same mechanism was supposed to be acting in the anti-malignant tumor activity in vivo and in vitro of dibutyltin compounds.4. Nickel bound to the low-molecular-nickel-binding substance showed a strong carcinogenic activitiy to cultured BALB/C 3T3 cells in contrast to no induction of transformation by inorganic nickel compounds.