Mitrović D M, Redzić Z B, Marković I D, Jovanović S S, Rosić M A, Rakić L M
Department of Physiology, School of Medicine, Belgrade University, Yugoslavia.
J Chemother. 1995 Dec;7(6):543-8. doi: 10.1179/joc.1995.7.6.543.
Tiazofurine is a selective inhibitor of the enzyme inosine monophosphate dehydrogenase, and exhibits potent antitumor activity. Considering the potential side effects on the heart, [3H] tiazofurine uptake into the cardiomyocytes, as well as the mechanism of transport, were studied in the isolated perfused guinea pig heart, using the rapid single circulation, paired-tracer technique. The maximal cellular uptake (Umax) of [3H] tiazofurine ranged from 19% to 25% of the injected dose, with total cellular uptake (Utot) ranging 12.1-15.6%. The addition of unlabeled tiazofurine caused inhibition of [3H] tiazofurine uptake, with a Umax value of 9.06 +/- 4.6%. Therefore, the uptake of tiazofurine into cardiomyocytes could be considered a saturable process. The inhibition of [3H] tiazofurine uptake caused by adenosine and dipyridamole was of the same degree as the inhibition by unlabeled tiazofurine. Thus, it can be assumed that nucleosides' transport system(s) are involved in transport of tiazofurine into myocardial cells.
替扎呋喃是肌苷单磷酸脱氢酶的选择性抑制剂，具有强大的抗肿瘤活性。考虑到其对心脏的潜在副作用，采用快速单次循环、双示踪技术，在离体灌注豚鼠心脏中研究了[3H]替扎呋喃进入心肌细胞的情况及其转运机制。[3H]替扎呋喃的最大细胞摄取量（Umax）为注射剂量的19%至25%，总细胞摄取量（Utot）为12.1 - 15.6%。加入未标记的替扎呋喃会抑制[3H]替扎呋喃的摄取，Umax值为9.06 +/- 4.6%。因此，替扎呋喃进入心肌细胞的摄取可被视为一个可饱和过程。腺苷和双嘧达莫对[3H]替扎呋喃摄取的抑制程度与未标记替扎呋喃的抑制程度相同。因此，可以假定核苷转运系统参与了替扎呋喃进入心肌细胞的转运。
