高钾溶液对猪冠状动脉内皮细胞功能影响的实验研究

Effects of High Potassium Solution on Endothelium Function in Porcine Coronary A rteries

目的 :探讨高钾溶液对猪冠状动脉内皮细胞功能的影响及其机制。方法 :取新鲜猪心外膜下冠状动脉前降支下三分之一 ,切成 3mm长的血管环。采用器官槽法 ,分别用Krebs Henseleit重碳酸盐缓冲液 (KH)、2 0mmol/L的高钾溶液、50mmol/L的高钾溶液浸泡血管环 1h后 ,检测在 7μmol/L环加氧酶阻断剂消炎痛、3 0 0 μmol/L一氧化氮合成酶阻断剂N 硝基 L 精氨酸、1mmol/L钙激动性钾通道阻断剂四乙胺、或 3μmol/LATP敏感性钾通道阻断剂优降糖的作用下 ,3 0nmol/L前列腺素F2α引发的预收缩强度和非受体介导钙离子载体 ( 10 -1 0 ～ 10 -6mol/L)引发的内皮源性舒张反应。结果 :与单纯浸泡于KH的冠状动脉相比 ,内皮源性超极化因子 (EDHF)介导的内皮源性舒张反应 ,经 2 0mmol/L、50mmol/L高钾溶液及四乙胺作用后显著降低 ,但加入优降糖后改变不明显。结论 :EDHF在冠状动脉内皮源性舒张中起重要的作用 ,高浓度钾离子抑制EDHF的作用。

Investigate effects of high potassium solution on end othelium function in porcine coronary arteries and the possible mechanism. Method: Porcine coronary artery rings was studied in the organ c hambers.After incubation with Krebs Henseleit (KH),20 or 50 mol/L K + for 1 ho ur,Relaxation in response to the EDHF stimuli A23187 in U46619 induced preconr taction in the presence of 7 μmol/L indomethacin (a cyclooxygenase inhibitor) a nd 300 μmol/L LNNA (a nitric oxide biosyhnthesis inhibitor),1 mmol/L tetraethyl amm onium (a Ca 2+ activated K + channel blocker),or 3 μmol/L glibenclamide (a n ATP sensitive K + channel blocker),was compared.Results: The relaxation could be further inhibited by tetraethyl ammonium,and 20 or 50 mmol/L K +,but not glibenclamide. Conclusion: Endothelium derived hyperpolarizing factors (EDHF ) mediated relaxation in coronary arteries are reduced by exposure to hyperkal emia;Ca 2+ activated K + channels are likely to be involved in EDHF mediat ed relaxation in coronary arteries.