氯胺酮对大鼠心肌细胞搏动频率及存活率的影响

Effects of Ketamine on Contracting Frequency and Survival Rate in Rat Cardiomyocytes

目的 观察不同剂量的氯胺酮对大鼠心肌细胞搏动频率及存活率的影响,探讨其心肌变时效应以及是否存在细胞毒性。方法 ①取原代培养的SD大鼠心室肌细胞,随机分为6组,即对照组、1μmol/L、10μmol/L、60μmol/L、100μmol/L和300μmol/L氯胺酮组(n=15孔),在倒置相差显微镜下分别计数氯胺酮作用前及作用30min后心肌细胞的搏动频率。②原代培养的SD大鼠心室肌细胞,随机分为5组,即对照组、10μmol/L、60μmol/L、100μmol/L、300μmol/L氯胺酮组(n=16孔),用四唑盐比色法在酶标仪上测定氯胺酮作用1h后各组细胞的光密度值。结果 ①1μmol/L、10μmol/L、60μmol/L和100μmol/L氯胺酮组,给药前后心肌细胞搏动频率无明显变化(P>0.05);300μmol/L氯胺酮组心肌细胞的搏动频率由给药前的(104.5±4.2)/min减慢至(98.2±4.0)/min(P<0.01);②10μmol/L、60μmol/氯胺酮组光密度值与对照组比较无显著性差异(P>0.05);而100μmol/L、300μmol/L氨胺酮组光密度值分别较对照组降低9.9％(P<0.05)和16.1％(P<0.01)。结论 ①≤100μmol/L的氯胺酮不影响心肌细胞的搏动频率;300μmol/L的氯胺酮对心肌细胞起负性变时效应;②高浓度、超临床浓度的氯胺酮降低心肌细胞的存活率,可能有一定的心肌毒性。

Objective To explore the chronotropic effect and toxicity profile of ketamine on myocardium , the contracting frequency and survival rate of cultured rat cardiomyocytes were observed. Methods ①Four to seven old-day spontaneously contracting primary cultured ventricular myocytes obtained from neonatal SD rats, were randomly divided into six groups. Equal volume of DMEM without fetal calf serum (FCS) was given as control. Different doses of ketamine (1 μmol/L、10 μmol/L、60 μmol/L、100μmol/L and 300 μmol/L) were administered in the other five groups ( n = 15). Contracting frequency were recorded on inverted microscope before and 30 minutes after different doses of ketamine were administered . ② Primary cultured SD rat ventricular myocytes were randomly divied into five groups. Equal volume of DMEM without FCS was used as control. Different doses of ketamine (10 μmol/L、60 μmol/L、100 μmol/L and 300 μmol/L) were administered in the other four groups ( n - 16) . Optical density (OD) values were tested as parameter of cell survival rate by MTT method with ELISA scanner after ketamine pre-incubated for one hour. Results ①No significant influence on contracting frequency in cardiomyocytes was observed after ketamine at 1 μmol/L、10μmol/L、60μmol/L and 100 μmol/L adminstered (P > 0.05); While katamine 300 μmol/L decreased contracting frequency from (104.5 ±4.2) /min to (98.2 ±4.0) /min (P <0.01);② There was no significant difference between OD values in 10 μmol/L、60μmol/L of ketamine groups and control group ( P > 0.05). However, OD values in 100 μmol/L、300μmol/L of ketamine groups deceased by 9.9% (P < 0.05) and 16.1% (P < 0.01) respectively, as compared with that of control group. Conclusion ①Ketamine at 1 μmol/L、10 μmol/L、60 μmol/L and 100 μmol/L do not influence contracting frequency of cardiomyocytes, while ketamine 300 μmol/L has negative chronotropic effect on cardiomyocytes; ② Ketamine at 100 μmol/L and 300 μmol/L decrease survival rates of cardiomyocytes.