Effects of caffeine on potassium currents in isolated rat ventricular myocytes
dc.contributor.author | Hussain, Munir | * |
dc.contributor.author | Chorvatova, A. | * |
dc.date.accessioned | 2009-07-14T09:31:23Z | |
dc.date.available | 2009-07-14T09:31:23Z | |
dc.date.issued | 2009-07-14 | |
dc.identifier.citation | Hussain, M., Chorvatova, A. (2003). Effects of caffeine on potassium currents in isolated rat ventricular myocytes. Pflugers Archiv European Journal of Physiology. Vol. 446, No. 4, pp. 422-428. | |
dc.identifier.uri | http://hdl.handle.net/10454/3003 | |
dc.description | No | |
dc.description.abstract | Rapid exposure of cardiac muscle to high concentrations of caffeine releases Ca 2+ from the sarcoplasmic reticulum (SR). This Ca 2+ is then extruded from the cell by the Na +/Ca 2+ exchanger. Measurement of the current carried by the exchanger ( I Na/Ca) can therefore be used to estimate of the Ca 2+ content of the SR. Previous studies have shown that caffeine, however, can also inhibit K + currents. We therefore investigated whether the inhibitory effects of caffeine on these currents could contaminate measurements of I Na/Ca. Caffeine caused partial inhibition of the inward rectifier K + current ( I K1): the outward current at ¿40 mV was 1.15±0.24 pA/pF in control and decreased to 0.34±0.15 pA/pF in the presence of 10 mmol/l caffeine ( P<0.05, n=15). This was similar to the effect of caffeine on the holding current observed at ¿40 mV in the absence of K + channel block and could therefore account for the contaminating effects of caffeine observed during measurements of I Na/Ca. Moreover, caffeine also partially inhibited the transient outward ( I to) and the delayed rectifier ( I K) K + currents. | |
dc.language.iso | en | |
dc.subject | Caffeine | |
dc.subject | Potassium Currents | |
dc.subject | Rat Ventricular | |
dc.subject | Myocytes | |
dc.subject | Cardiac Muscle | |
dc.subject | Calcium Ion | |
dc.subject | Sodium/Potassium exchanger | |
dc.title | Effects of caffeine on potassium currents in isolated rat ventricular myocytes | |
dc.status.refereed | Yes | |
dc.type | Article | |
dc.type.version | No full-text in the repository | |
dc.identifier.doi | https://doi.org/10.1007/s00424-003-1031-1 | |
dc.openaccess.status | closedAccess |