Sex differences in L-type calcium current after chronic ethanol consumption in rats.
Chronic ethanol consumption elicits a progressive cardiac contractile dysfunction, and studies in rats suggest that this alcoholic heart muscle disease is more pronounced in males than females. Cellular changes associated with the ethanol-induced cardiotoxicity remain largely undefined; however, it is possible that L-type Ca(2+) channel current (I(Ca,L)) is affected. Using whole-cell patch-clamp techniques, this study examined I(Ca,L) in adult ventricular myocytes isolated from male and female P-rats that had consumed drinking water (controls) or a 25% ethanol/water mixture for 14 months. The peak amplitude and maximum conductance of I(Ca,L) were 32 and 26% greater, respectively, in cardiomyocytes isolated from ethanol-consuming compared to control male rats. In contrast, no differences in the amplitude or conductance of I(Ca,L) were observed when comparing myocytes isolated from control and ethanol-consuming females. Ethanol treatment had no significant effects on the kinetics I(Ca,L) inactivation or on steady-state activation and inactivation in either gender. In conclusion, male but not female cardiomyocytes respond to chronic ethanol consumption with an increased I(Ca,L) that may represent a compensatory response to the depressed contractility.
Kennedy
Richard H
RH
Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock 72205, USA. KennedyRichardH@uams.edu
Liu
Shi J
SJ
D000428:Alcohol Drinking / Q000235:genetics / Q000503:physiopathology; D000818:Animals; D020746:Calcium Channels, L-Type / Q000502:physiology*; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D008297:Male; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000502:physiology; D051381:Rats; D012727:Sex Characteristics
D020746:Calcium Channels, L-Type; D000431:Ethanol