van Meel J C, Redemann N, Diederen W, Haigh R M
Molecular Pharmacology Group, Dr. Karl Thomae GmbH, Biberach/Riss, Germany.
Naunyn Schmiedebergs Arch Pharmacol. 1995 Jun;351(6):644-50. doi: 10.1007/BF00170165.
Recent data show that UD-CG 212 in nanomolar concentrations increases myofibrillar Ca++ responsiveness of chemically skinned cardiac preparations in the presence of elevated inorganic phosphate. We studied the effects of UD-CG 212 on cell shortening of intact myocytes and in addition measured the intracellular calcium transients with the aid of INDO-1 fluorescence in the presence of 5 mM inorganic phosphate. The validity of our experimental system was first tested with the calcium channel opener Bay k 8644. Bay k 8644 at 10(-8) M did not significantly influence myocyte shortening (+ 13.9 +/- 4.6%, n = 9) but at 10(-7) M and 10(-6) M significantly increased contraction by 40.1 +/- 13.6% and 52.5 +/- 17.0% respectively. Bay k 8644 at 10(-8) M increased the INDO-1 fluorescence ratio by 17.3 +/- 4.7% (P < 0.01; n = 9), and at 10(-7) M by 21.5 +/- 4.3% (P < 0.01; n = 9), whereas 10(-6) M Bay k 8644 had no significant effect on peak INDO-1 ratio. However, 10(-7) and 10(-6) M Bay k 8644 accelerated and broadened the calcium transients.(ABSTRACT TRUNCATED AT 250 WORDS)
近期数据表明，在无机磷酸盐浓度升高的情况下，纳摩尔浓度的UD - CG 212可增加化学去膜心脏制剂的肌原纤维对钙离子的反应性。我们研究了UD - CG 212对完整心肌细胞缩短的影响，并借助indo - 1荧光在5 mM无机磷酸盐存在的情况下测量了细胞内钙瞬变。我们首先用钙通道开放剂Bay k 8644测试了我们实验系统的有效性。10(-8) M的Bay k 8644对心肌细胞缩短没有显著影响（增加13.9±4.6%，n = 9），但在10(-7) M和10(-6) M时分别显著增加收缩40.1±13.6%和52.5±17.0%。10(-8) M的Bay k 8644使indo - 1荧光比率增加17.3±4.7%（P < 0.01；n = 9），10(-7) M时增加21.5±4.3%（P < 0.01；n = 9），而10(-6) M的Bay k 8644对indo - 1峰值比率没有显著影响。然而，10(-7)和10(-6) M的Bay k 8644加速并拓宽了钙瞬变。（摘要截断于250字）
