Colquhoun A, Newsholme E A
Department of Biochemistry, University of Oxford, U.K.
Cell Biochem Funct. 1997 Jun;15(2):135-9. doi: 10.1002/(SICI)1099-0844(19970601)15:2<135::AID-CBF733>3.0.CO;2-G.
The effects of adenosine and several structural analogues of adenosine upon thymidine incorporation into human tumour cells and rat cervical lymphocytes were investigated. The analogue NECA, which has equal specificity for the A1 and A2 receptor, had the most inhibitory effect on lymphocyte proliferation while the A1 agonists had limited effects, suggesting that these cells possess principally A2 adenosine receptors. In the case of human tumour cells, however, the most inhibitory effect on proliferation was obtained with the A1-specific analogues. The general order of inhibitory effects of adenosine analogues on thymidine incorporation in human tumour cells was: S-ENBA > CPA = R-PIA > S-PIA > NECA. These findings suggest that in the cells presently studied the A1 adenosine receptor predominates. Removal of exogenous adenosine by growth in the presence of adenosine deaminase inhibited thymidine incorporation. The effect of adenosine removal lends further support to the proposal that adenosine has some, as yet unidentified, regulatory role in the control of human tumour cell proliferation.
研究了腺苷及其几种结构类似物对胸苷掺入人肿瘤细胞和大鼠宫颈淋巴细胞的影响。对A1和A2受体具有同等特异性的类似物NECA对淋巴细胞增殖的抑制作用最强，而A1激动剂的作用有限，这表明这些细胞主要具有A2腺苷受体。然而，在人肿瘤细胞中，对增殖抑制作用最强的是A1特异性类似物。腺苷类似物对人肿瘤细胞胸苷掺入的抑制作用总体顺序为：S-ENBA > CPA = R-PIA > S-PIA > NECA。这些发现表明，在目前研究的细胞中，A1腺苷受体占主导地位。在腺苷脱氨酶存在的情况下生长以去除外源性腺苷会抑制胸苷掺入。去除腺苷的作用进一步支持了腺苷在控制人肿瘤细胞增殖中具有某种尚未明确的调节作用这一观点。
