Human keratinocytes catabolize thymidine.
Human keratinocytes catabolize thymidine.
复制标题
人类角质形成细胞分解代谢胸苷。
DOI：
10.1111/1523-1747.ep12462412
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Milstone,LM
中科院分区：
文献类型：
--
作者：
Schwartz,PM;Kugelman,LC;Coifman,Y;Hough,LM;Milstone,LM
人新生儿包皮角质形成细胞将外源性胸腺嘧啶核苷掺入DNA中，即使在达到融合后也能在体外增殖。角质形成细胞也分解胸腺嘧啶核苷，如下首次报道。角质形成细胞的分层培养在2~4h内可使培养液中胸腺嘧啶核苷的含量降低90%以上，因此，胸腺嘧啶核苷(0.2μM，4μCi/ml)的掺入速率在2 h内呈线性关系，继续加入新鲜的放射性胸腺嘧啶核苷可使胸腺嘧啶核苷线性掺入至少12 h。不同的组织分解胸腺嘧啶核苷的能力差异很大。胸腺嘧啶核苷的皮肤分解代谢表现出显著的物种差异。人类新生儿包皮和成人皮肤以及培养的人类角质形成细胞的可溶性提取物能有效分解胸腺嘧啶核苷。小鼠、兔或豚鼠皮肤的可溶性提取物不分解胸苷。培养的人成纤维细胞和黑素细胞的提取物很少或根本没有分解胸腺嘧啶核苷的能力。角质形成细胞对胸腺嘧啶核苷的分解代谢对研究角质形成细胞增殖和胸腺嘧啶核苷类似物治疗皮肤病具有重要意义。
Human neonatal foreskin keratinocytes incorporate exogenous thymidine into DNA and proliferate in vitro even after reaching confluence. Keratinocytes also catabolize thymidine, as reported for the first time below. Stratified cultures of keratinocytes reduced the amount of thymidine in the medium by more than 90% within 2 to 4 h. Consequently, the rate of incorporation of thymidine (0.2 μM, 4 μCi/ml) into DNA was linear for no more than 2 h. Linear incorporation of thymidine into DNA for at least 12 h could be achieved by continual addition of fresh radioactive thymidine to the culture medium. Different tissues have widely differing abilities to catabolize thymidine. Cutaneous catabolism of thymidine shows striking species differences. Soluble extracts from human neonatal foreskin and adult skin, as well as from cultivated human keratinocytes, actively catabolize thymidine. Soluble extracts of skin from mouse, rabbit, or guinea pig do not catabolize thymidine. Extracts from cultivated human fibroblasts and melanocytes have little or no ability to catabolize thymidine. Catabolism of thymidine by keratinocytes has important implications for the use of [3H]thymidine in studies of keratinocyte proliferation and for the use of thymidine analogs in therapy of cutaneous disease.