Pincheira J, Gallo C, Bravo M, Navarrete M H, Lopez-Saez J F
Depto. de Biología Celular y Genética, Facultad de Medicina, Universidad de Chile, Santiago.
Mutat Res. 1993 Mar;295(2):55-62. doi: 10.1016/0921-8734(93)90001-j.
The caffeine effects on chromosomal aberration frequency and mean G2 duration were studied in human lymphocytes in vitro from three age groups of normal donors (I: 1-5 years old; II: 30-40 years old; III: 60-70 years old). Under control conditions, the three age groups showed a similar frequency of chromosomal aberrations. All three age groups exhibited a linear dose response for aberrations with caffeine treatments. However, lymphocytes from aged individuals (groups II and III) showed higher chromosomal aberration frequencies and longer G2 duration than cells from young individuals (group I). The caffeine effect in reducing G2 length was rather similar in every age group. The reversion of caffeine effects by adenosine or niacinamide in lymphocytes from older individuals was higher than in cells from group I. The different caffeine effects and G2 values between lymphocytes from old and young individuals are most likely due to a higher number of DNA lesions reaching G2 phase and/or a decrease of the G2 repair capability of lymphocytes from older individuals.
研究了咖啡因对来自三个年龄组正常供体（I组：1 - 5岁；II组：30 - 40岁；III组：60 - 70岁）的人外周血淋巴细胞染色体畸变频率和平均G2期持续时间的影响。在对照条件下，三个年龄组的染色体畸变频率相似。在咖啡因处理下，所有三个年龄组的畸变均呈现线性剂量反应。然而，老年个体（II组和III组）的淋巴细胞比年轻个体（I组）的细胞表现出更高的染色体畸变频率和更长的G2期持续时间。咖啡因对缩短G2期长度的作用在每个年龄组中相当相似。腺苷或烟酰胺对老年个体淋巴细胞中咖啡因作用的逆转作用高于I组细胞。老年和年轻个体淋巴细胞之间咖啡因作用和G2值的差异很可能是由于进入G2期的DNA损伤数量较多和/或老年个体淋巴细胞的G2期修复能力下降所致。
