Púzserová A, Csizmadiová Z, Bernátová I
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Bratislava, Slovak Republic.
Physiol Res. 2007;56 Suppl 2:S77-S84. doi: 10.33549/physiolres.931401. Epub 2007 Sep 5.
The aim of this study was to investigate nitric oxide (NO) production and L-NAME-sensitive component of endothelium-dependent vasorelaxation in adult normotensive Wistar-Kyoto rats (WKY), borderline hypertensive rats (BHR) and spontaneously hypertensive rats (SHR). Blood pressure (BP) of WKY, BHR and SHR (determined by tail-cuff) was 111+/-3, 140+/-4 and 184+/-6 mm Hg, respectively. NO synthase activity (determined by conversion of [(3)H]-L-arginine) was significantly higher in the aorta of BHR and SHR vs. WKY and in the left ventricle of SHR vs. both BHR and WKY. L-NAME-sensitive component of endothelium-dependent relaxation was investigated in the preconstricted femoral arteries using the wire myograph during isometric conditions as a difference between acetylcholine-induced relaxation before and after acute N(G)-nitro-L-arginine methyl ester pre-treatment (L-NAME, 10(-5) mol/l). Acetylcholine-induced vasorelaxation of SHR was significantly greater than that in WKY. L-NAME-sensitive component of vasorelaxation in WKY, BHR and SHR was 20+/-3 %, 29+/-4 % (p<0.05 vs. WKY) and 37+/-3 % (p<0.05 vs. BHR), respectively. There was a significant positive correlation between BP and L-NAME-sensitive component of relaxation of the femoral artery. In conclusion, results suggest the absence of endothelial dysfunction in the femoral artery of adult borderline and spontaneously hypertensive rats and gradual elevation of L-NAME-sensitive component of vasorelaxation with increasing blood pressure.
本研究旨在调查成年正常血压的Wistar-Kyoto大鼠（WKY）、临界高血压大鼠（BHR）和自发性高血压大鼠（SHR）中一氧化氮（NO）的生成以及内皮依赖性血管舒张的L-NAME敏感成分。通过尾套法测定，WKY、BHR和SHR的血压（BP）分别为111±3、140±4和184±6 mmHg。与WKY相比，BHR和SHR主动脉中的NO合酶活性（通过[(3)H]-L-精氨酸的转化来测定）显著更高，与BHR和WKY相比，SHR左心室中的NO合酶活性也显著更高。在等长条件下，使用线肌动描记器在预收缩的股动脉中研究内皮依赖性舒张的L-NAME敏感成分，作为急性N(G)-硝基-L-精氨酸甲酯预处理（L-NAME，10(-5) mol/l）前后乙酰胆碱诱导的舒张之间的差异。SHR中乙酰胆碱诱导的血管舒张显著大于WKY。WKY、BHR和SHR中血管舒张的L-NAME敏感成分分别为20±3%、29±4%（与WKY相比，p<0.05）和37±3%（与BHR相比，p<0.05）。股动脉血压与L-NAME敏感的舒张成分之间存在显著正相关。总之，结果表明成年临界高血压和自发性高血压大鼠的股动脉不存在内皮功能障碍，并且随着血压升高，血管舒张的L-NAME敏感成分逐渐升高。
