【摘要】 目的 :探讨氯胺酮对人单个心房肌细胞ATP敏感性钾电流 (IK·ATP)的影响 .方法 :取房缺或室缺修补术患者的右心耳组织 ,置于 1 0 0 %氧饱和的无钙心肌细胞保护液中 ,30min内送至实验室 .将标本剪成 1mm3 的小块 ,用二步酶解法分离出单个心房肌细胞 .采用膜片钳全细胞记录方法 ,观察两种浓度氯胺酮对人单个心房肌细胞IK .ATP的影响 .结果 :在电极内液含ATP(0 .3mmol·L-1 )的条件下 ,记录到一束外向K+ 电流 .该电流可被KATP通道特异阻滞药格列苯脲 (1 0 μmol·L-1 )抑制 ,表明此电流为IK·ATP.在指令电位为 +2 0mV时 ,用含低浓度氯胺酮 (0 .0 1mmol·L-1 )的细胞外液灌流时 ,IK·ATP受到抑制 ,抑制率为 1 1 .1 % (n =3,P <0 .0 1 ) .用含高浓度氯胺酮(0 .1mmol·L-1 )的细胞外液灌流时 ,IK·ATP被大量激活 ,增加率为 5 7.6 % (n =3,P <0 .0 1 ) .结论 :低浓度氯胺酮 (0 .0 1mmol·L-1 )对人心房肌细胞IK·ATP具有抑制作用 ;高浓度氯胺酮 (0 .1mmol·L-1 )对IK·ATP则有激活作用更多还原

【Abstract】 AIM: To investigate the effect of ketamine on ATP sensitive K + currents ( I KATP ) in human single atrial myocyte. METHODS: Right auricle of heart samples were obtained from patients who underwent atrial septal defect (ASD) or ventricular septal defect(VSD) repair surgery. Myocardial samples were quickly placed in Ca 2+ free cardioplegic solution bubbled with 100% oxygen and were transferred to lab in 30 minutes. The samples were chopped into small chunks (1 mm 3 )with fine scissors. Single atrial myocyte was isolated with enzymatic dissociation techniques. Effects of ketamine on I K·ATP in single atrial myocyte was studied using the whole cell configuration of patch clamp technique. RESULTS: Outward currents were recorded with 0.3 mmol·L -1 ATP in pipette solution. The currents were inhibited by glibenclamide (10 μmol·L -1 ) , which is specific inhibitor of K ATP channels, suggesting that the outward currents were I K·ATP . Under the ordered voltage at +20 mV, when perfused with the external solution containing ketamine in low concentration (0.01 mmol·L -1 ), the I K·ATP was reduced by 11.1%( n =3), while perfused with the external solution containing ketamine in high concentration (0.1 mmol·L -1 ), the I K·ATP was significantly increased by 57.6% ( n =3).CONCLUSION: Ketamine in low concentration inhibits I K·ATP , and in high concentration, increases I K·ATP in human atrial myocytes.更多还原