Yoshida K, Iwase J, Murakami F, Usui A, Hibi M, Kawamura M
Department of Cardiovascular Surgery, Owari Hospital, Aichi, Japan.
Surg Today. 1994;24(12):1073-7. doi: 10.1007/BF01367458.
The effects of calcium antagonists (nifedipine, nicardipine, diltiazem, and verapamil) and prostaglandin E1 (PGE1) on the tension of isolated canine coronary arterial strips were studied. In a solution containing 20 mEq/L of K+, 127 mEq/L of Na+, the tension was increased by 500-1,000 mg with 4 mEq/L of Ca2+. This increase in tension was suppressed by Ca-antagonists and PGE1 dose-dependently. Nifedipine 10(-5) M, nicardipine 3 x 10(-7) M, diltiazem 3 x 10(-6) M, and verapamil 3 x 10(-6) M completely suppressed the increased tension. The maximal suppression of the tension produced by PGE1 was about 40% at 10(-10) M. In 20 mEq/L K+ solution (0 mEq/L Ca2+, 37 degrees C), the reduction of the Na+ concentrations from 127 mEq/L to 12 mEq/L increased the tension by 50 to 100 mg. This increase in tension was not suppressed by Ca-antagonists or PGE1. In conclusion, this study demonstrated that Ca-antagonists and PGE1 suppressed an increase in the tension caused by Ca2+ but did not suppress an increase in the tension caused by Na+ reduction.
研究了钙拮抗剂（硝苯地平、尼卡地平、地尔硫卓和维拉帕米）和前列腺素E1（PGE1）对离体犬冠状动脉条张力的影响。在含有20 mEq/L钾离子、127 mEq/L钠离子的溶液中，加入4 mEq/L钙离子可使张力增加500 - 1000 mg。钙拮抗剂和PGE1可剂量依赖性地抑制这种张力增加。硝苯地平10(-5) M、尼卡地平3×10(-7) M、地尔硫卓3×10(-6) M和维拉帕米3×10(-6) M可完全抑制张力增加。PGE1在10(-10) M时对张力的最大抑制约为40%。在20 mEq/L钾离子溶液（0 mEq/L钙离子，37℃）中，将钠离子浓度从127 mEq/L降至12 mEq/L可使张力增加50至100 mg。这种张力增加不受钙拮抗剂或PGE1的抑制。总之，本研究表明钙拮抗剂和PGE1可抑制由钙离子引起的张力增加，但不能抑制由钠离子减少引起的张力增加。
