【摘要】 目的　研究离体培养的乳鼠单个收缩心肌细胞搏动近日节律是否受褪黑素及安定的影响 ,探讨细胞水平自激振荡节律调节机制。方法　运用电子成像技术 2 4 h在六个时间点 (0 0∶ 0 0 ;0 4∶ 0 0 ;0 8∶ 0 0 ;12∶ 0 0 ;16∶0 0 ;2 0∶ 0 0 )动态监测单个离体的收缩心肌细胞搏动频率 ,分别用浓度为 10 - 8mol/L、10 - 6 mol/L,10 - 4m ol/L 的褪黑素及安定对其进行干预 ,所得数据均采用时间生物学余弦分析法计算。结果　发现褪黑素及安定对单个收缩心肌细胞搏动近日节律的振幅及相位均有影响 ,使其振幅、中值减小 ,相位后移。结论　单个收缩心肌细胞内固有的自激振荡节律 (细胞搏动近日节律 )可被褪黑素及安定导引 ,其细胞水平的自激振荡节律不仅受内源性因素调控 ,而且受外源性因素所影响更多还原

【Abstract】 Objective To investigate the effect of melatonin and/or diazepam on the endogenous rhythm in cultured myocardiocytes and in that connexion to inquire into the mechanism of circadian oscillation level. Methods The beating rate of cultured myocardiocytes was dynamically monitored by an inverted phase contrast microscope coupled to high speed CCD camera and computer system. Under the culturing condition of artificial light L∶D= 12∶ 12, the circadian rhythm variation of cultured myocardiocytes beating frequencies was measured, and then the effect exerted by melatonin and/or diazepam on that circadian rhythm was studied. Results It was found that under the L∶D=12∶12 culturing condition, the cultured myocardiocytes exhibited prominent circadian rhythm. With the use of melatonin and or diazepam, the circadian rhythm of those myocardiocytes changed, not only the amplitude and mesor decreased, but also the acrophase delayed. Conclusion The modulation of circadian rhythm in cellular level is not only related with endogenous control but also affected by external factors.更多还原