Henrion D, Laher I
Department of Pharmacology, University of Vermont, College of Medicine, Burlington 05405-0068.
Can J Physiol Pharmacol. 1993 Jul;71(7):521-4. doi: 10.1139/y93-076.
In isolated rings of the rabbit facial vein, facial artery, and aorta, calphostin C and staurosporine, inhibitors of protein kinase C, reduced myogenic tone and norepinephrine (1 microM), K+ (80 mM), and Ca2+ (1.6 mM) induced tone. In all instances, staurosporine was more potent than calphostin C. In contrast to staurosporine, the IC50 value of calphostin C against myogenic tone was similar to that recorded for protein kinase C in biochemical studies (0.086 vs. 0.050 microM) and the average IC50 values of calphostin C against norepinephrine (2.2 microM), K+ (3.3 microM), and Ca2+ (4.3 microM) in the three vessels were similar to that for myosin light-chain kinase in biochemical studies (> 5.0 microM). In the facial vein, calphostin C was 59-fold more potent against myogenic tone than against Ca(2+)-induced tone and 8-fold more specific for myogenic tone than was staurosporine. In addition, at concentrations not affecting K+ (80 mM) induced tone, calphostin C suppressed 1-oleoyl-2-acetyl-sn-glycerol induced tone in the facial vein, whereas staurosporine only attenuated it by 65%. Thus calphostin C inhibits protein kinase C dependent tone in isolated blood vessels to a greater extent than does staurosporine.
在兔面静脉、面动脉和主动脉的离体血管环中，蛋白激酶C抑制剂钙泊三醇C和星形孢菌素可降低肌源性张力以及去甲肾上腺素（1微摩尔）、钾离子（80毫摩尔）和钙离子（1.6毫摩尔）诱导的张力。在所有情况下，星形孢菌素比钙泊三醇C更有效。与星形孢菌素不同，钙泊三醇C对肌源性张力的半数抑制浓度（IC50）值与生化研究中记录的蛋白激酶C的IC50值相似（0.086对0.050微摩尔），并且在这三种血管中，钙泊三醇C对去甲肾上腺素（2.2微摩尔）、钾离子（3.3微摩尔）和钙离子（4.3微摩尔）的平均IC50值与生化研究中肌球蛋白轻链激酶的IC50值相似（>5.0微摩尔）。在面静脉中，钙泊三醇C对肌源性张力的效力比对钙离子诱导的张力高59倍，对肌源性张力的特异性比星形孢菌素高8倍。此外，在不影响钾离子（80毫摩尔）诱导张力的浓度下，钙泊三醇C可抑制面静脉中1-油酰基-2-乙酰基-sn-甘油诱导的张力，而星形孢菌素仅使其减弱65%。因此，钙泊三醇C比星形孢菌素在更大程度上抑制离体血管中依赖蛋白激酶C的张力。
