Ahlner J, Axelsson K L, Karlsson J G, Andersson R G
Department of Clinical Pharmacology, University Hospital, Linköping, Sweden.
Life Sci. 1988;43(15):1241-8. doi: 10.1016/0024-3205(88)90214-7.
The effect of glyceryl trinitrate (GTN) on relaxation, cGMP levels, phosphorylase a activity, phosphatidylinositol hydrolysis and protein kinase C activity was studied on isolated bovine mesenteric arteries (BMA). Two concentrations of GTN were tested, 0.1 nM representing a high affinity component and 1 microM representing a low affinity component of the GTN induced relaxation of BMA, giving a relaxation of 20% and 60% and a 2-fold and 5-fold increase in cGMP, respectively. Phosphatidylinositol hydrolysis and protein kinase C activity were significantly, and to the same extent, reduced at both concentrations tested, whereas the phosphorylase a activity was significantly reduced at the higher concentration only, which might indicate a reduction of the free intracellular Ca2+-concentration at high concentrations of GTN. It is concluded that a therapeutically relevant concentration (0.1 nM) of GTN induces relaxation and an increase in cGMP in bovine mesenteric arteries. The relaxation seems to be associated with an inhibition of phosphatidylinositol hydrolysis and a reduction of the protein kinase C activity.
研究了硝酸甘油（GTN）对离体牛肠系膜动脉（BMA）舒张、环磷酸鸟苷（cGMP）水平、磷酸化酶a活性、磷脂酰肌醇水解及蛋白激酶C活性的影响。测试了两种浓度的GTN，0.1 nM代表GTN诱导BMA舒张的高亲和力成分，1 μM代表低亲和力成分，分别使BMA舒张20%和60%，cGMP分别增加2倍和5倍。在所测试的两种浓度下，磷脂酰肌醇水解和蛋白激酶C活性均显著且程度相同地降低，而仅在较高浓度下磷酸化酶a活性显著降低，这可能表明在高浓度GTN下细胞内游离钙离子浓度降低。结论是，治疗相关浓度（0.1 nM）的GTN可诱导牛肠系膜动脉舒张并使cGMP增加。这种舒张似乎与磷脂酰肌醇水解的抑制和蛋白激酶C活性的降低有关。
