科研之友
微信
新浪微博
Facebook
分享链接
摘要
HL-1 is a line of immortalized cells of cardiomyocyte origin that are a useful complement to native cardiomyocytes in studies of cardiac gene regulation. Several types of ion channel have been identified in these cells, but not the physiologically important inward rectifier K(+) channels. Our aim was to identify and characterize inward rectifier K(+) channels in HL-1 cells. External Ba(2+) (100 mu M) inhibited 44 +/- 0.05% (mean +/- s.e.m., n = 11) of inward current in whole-cell patch-clamp recordings. The reversal potential of the Ba(2+)-sensitive current shifted with external [K(+)] as expected for K(+)-selective channels. The slope conductance of the inward Ba(2+)-sensitive current increased with external [K(+)]. The apparent Kd for Ba(2+) was voltage dependent, ranging from 15 mu M at-150 mV to 148 mu M at-75 mV in 120 mM external K(+). This current was insensitive to 10 mu M glybenclamide. A component of whole-cell current was sensitive to 150 mu M 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), although it did not correspond to the Ba2(+)-sensitive component. The effect of external 1 mM Cs(-) was similar to that of Ba(2+) Polymerase chain reaction using HL-1 cDNA as template and primers specific for the cardiac inward rectifier K(ir)2.1 produced a fragment of the expected size that was confirmed to be K(ir)2.1 by DNA sequencing. In conclusion, HL-1 cells express a current that is characteristic of cardiac inward rectifier K(+) channels, and express K(ir)2.1 mRNA. This cell line may have use as a system for studying inward rectifier gene regulation in a cardiomyocyte phenotype. J. Cell. Physiol. 225: 751-756, 2010.
- 出版日期2010-12
