Fujioka H, Horiike K, Takahashi M, Ishida T, Kinoshita M, Nozaki M
Department of Internal Medicine, Shiga University of Medical Science, Japan.
Experientia. 1993 Jan 15;49(1):47-50. doi: 10.1007/BF01928788.
The vascular effects of 2-mercaptoethanol, cysteamine, L-cysteine, glutathione (GSH), cystamine and oxidized GSH (GSSG) on the isometric tension of isolated dog coronary arterial strips were examined, and these effects were compared with the triphasic response induced by dithiothreitol (DTT); a rapid and weak contraction (phase A), an intervening slow relaxation (phase B) and a slowly-developing strong contraction (phase C) which we previously reported. The responses of the arteries induced by 2-mercaptoethanol, cysteamine and L-cysteine consisted of phases A, B and C. The order of contractile potency (ED50 of phase C) was DTT approximately L-cysteine > 2-mercaptoethanol approximately cysteamine, while the order of relaxant potency (ED50 of phase B) was DTT > cysteamine approximately 2-mercaptoethanol. GSSG and cystamine mainly produced relaxation, which corresponded to phase B. The phase C contraction was specific to the reduced forms of thiols, except for GSH, which produced only relaxation. The participation of endothelial cells was not essential for the contracting or relaxing effects of the thiol compounds. The phase C contraction was depressed by W-7, a calmodulin antagonist, while phase A was not. Therefore calmodulin-dependent protein kinases may participate in phase C, not in phase A.
研究了2-巯基乙醇、半胱胺、L-半胱氨酸、谷胱甘肽（GSH）、胱胺和氧化型谷胱甘肽（GSSG）对离体犬冠状动脉条等长张力的血管效应，并将这些效应与二硫苏糖醇（DTT）诱导的三相反应进行比较；三相反应包括快速且微弱的收缩（A相）、中间的缓慢舒张（B相）和缓慢发展的强烈收缩（C相），这是我们之前报道过的。2-巯基乙醇、半胱胺和L-半胱氨酸诱导的动脉反应包括A、B和C相。收缩效力顺序（C相的ED50）为DTT≈L-半胱氨酸＞2-巯基乙醇≈半胱胺，而舒张效力顺序（B相的ED50）为DTT＞半胱胺≈2-巯基乙醇。GSSG和胱胺主要产生舒张作用，这与B相对应。除了仅产生舒张作用的GSH外，C相收缩对硫醇的还原形式具有特异性。内皮细胞的参与对于硫醇化合物的收缩或舒张作用并非必需。C相收缩被钙调蛋白拮抗剂W-7抑制，而A相则未被抑制。因此，钙调蛋白依赖性蛋白激酶可能参与C相，而非A相。
