Oya Y, Yamamoto K
Department of Pathology, Kanagawa Prefectural College of Nursing and Medical Technology, Yokohama, Japan.
Mutat Res. 1988 Mar;198(1):233-40. doi: 10.1016/0027-5107(88)90060-7.
An enhancing effect of L-histidine (L-His) was detected on the induction by hydrogen peroxide (H2O2) of chromosomal aberrations of both the chromosome type and the chromatid type, in human embryonic fibroblasts. The maximum efficiency of induction was about 8-fold higher in the presence of L-His than in the presence of H2O2 alone, at a concentration of L-His of 50 microM. D-His and DL-His showed lower enhancing effects than L-His, with approximately 2-fold and 5-fold enhancement of induction of chromosomal aberrations, respectively. L-Histidinol and L-His-methyl ester, among various derivatives of L-His tested, also enhanced this process. However, the effects of these derivatives were smaller than those of L-His in a range of concentrations equivalent to that of the most effective dose of L-His (50 microM), while they produced greater enhancement than L-His at concentrations higher than 200 microM. Other derivatives of L-His, such as L-carnosine, urocanic acid, imidazolepyruvic acid, 1-methyl-L-His, imidazolelactic acid, imidazoleacetic acid and histamine and imidazole itself did not enhance the frequency of chromosomal aberrations induced by H2O2. These results indicate that at least both the imidazole ring and the amino group are essential components of the chemical structure of L-His required for the enhancing effect. Moreover, in order to cause such an enhancing effect, L-His had to be applied together with H2O2 to cells, because the enhancing effect of L-His was not observed with cells which were washed after pretreatment with L-His. The preliminary study suggested that this enhancing effect depends on the His-peroxide adduct derived from L-His and H2O2. None of the amino acids tested other than His produced any enhancing effect on the induction of chromosomal aberrations by H2O2.
在人胚胎成纤维细胞中，检测到L-组氨酸（L-His）对过氧化氢（H2O2）诱导的染色体型和染色单体型染色体畸变有增强作用。在L-His浓度为50微摩尔时，诱导的最大效率在L-His存在下比单独H2O2存在时高约8倍。D-His和DL-His的增强作用低于L-His，分别使染色体畸变诱导增强约2倍和5倍。在测试的L-His各种衍生物中，L-组氨醇和L-组氨酸甲酯也增强了这一过程。然而，在相当于L-His最有效剂量（50微摩尔）的浓度范围内，这些衍生物的作用比L-His小，而在高于200微摩尔的浓度下，它们产生的增强作用比L-His大。L-His的其他衍生物，如L-肌肽、尿刊酸、咪唑丙酮酸、1-甲基-L-组氨酸、咪唑乳酸、咪唑乙酸、组胺和咪唑本身并未增强H2O2诱导的染色体畸变频率。这些结果表明，至少咪唑环和氨基是L-His增强作用所需化学结构的必需组成部分。此外，为了产生这种增强作用，L-His必须与H2O2一起应用于细胞，因为在用L-His预处理后洗涤的细胞中未观察到L-His的增强作用。初步研究表明，这种增强作用取决于L-His和H2O2衍生的His-过氧化物加合物。除His外，测试的其他氨基酸均未对H2O2诱导的染色体畸变产生任何增强作用。
