Abstract:

Abstract:Objective To investigate the effects of sphingosine-1-phosphate(S1P) on single-aisle delayed rectifier K⁺ current in heart ventricular myocytes of guinea pigs and explore the role of S1P in ventricular arrhythmia.Methods The Langendorff perfusion method was used to isolate ventricular myocytes of guinea pigs and the ventricular myocytes were randomly divided into normal control group,S1P(2.2 μmol·L^-1) group and S1P(2.2 μmol·L^-1)+Suramin（200 μmol·L^-1）group.The current of delayed rectifier potassium channel was recorded by cell-attached recording.Results Compared with normal control group by cell-attached recording and respecting the channel dynamics,the opening dwell time and the opening probability decreased,while the closing dwell time increased in S1P group (P<0.05)；and there was no obviously difference between S1P+Suramin group and normal control group while respecting the channel dynamics（P>0.05）.Conclusion S1P inhibits delayed rectifier potassium current of ventricular myocytes of guinea pigs by shortening its opening dwell time,extending its closing dwell time and reducing the opening probability.And the functions above are mediated by membrane receptor.

Key words: sphingosine-1-phosphate;myocardium / cytology;patch clamp;delayed rectifier potassium channel