Saga K, Shimojo T
Arch Dermatol Res. 1984;276(3):165-9. doi: 10.1007/BF00414014.
The effect of theophylline, an inhibitor of phosphodiesterase, on tyrosine (Tyr) transport across cell membrane was studied using cultured B-16 mouse melanoma cells. 1.5 mM Theophylline in culture medium increased Tyr uptake velocity in linear fashion up to 36 h, after which it reached a plateau at which the cells showed about a 60% increase in Tyr transport velocity. This increase was independent of extracellular Na, essentially unaffected by cell density, and partially inhibited by concomitantly added cycloheximide. These results suggested that biosynthesis of macromolecules, probably acting as System L transporter, was induced by theophylline treatment.
使用培养的B - 16小鼠黑色素瘤细胞，研究了磷酸二酯酶抑制剂茶碱对酪氨酸（Tyr）跨细胞膜转运的影响。培养基中1.5 mM的茶碱以线性方式提高Tyr摄取速度，持续36小时，之后达到平台期，此时细胞的Tyr转运速度提高约60%。这种增加与细胞外钠无关，基本不受细胞密度影响，并被同时添加的环己酰亚胺部分抑制。这些结果表明，茶碱处理诱导了可能作为L系统转运体的大分子的生物合成。
