Depression of contraction and the calcium transient in single cardiomyocytes with acute ethanol exposure
- Thomas Jefferson Univ., Philadelphia, PA (United States)
The mechanism by which acute ethanol (ET) exposure causes reversible myocardial dysfunction is unknown. The purpose of this study was to examine the effects of ET exposure on contraction and cytosolic free Ca[sup 2+] ([Ca[sup 2+]][sub i]) in electrically-stimulated single rat ventricular myocytes loaded with the fluorescent Ca[sup 2+] indicator, fura-2. Whole cell fluorescence images were obtained at high speed with a frame transfer CCD camera and processed by a digital imaging system which allowed simultaneous measurement of cell shortening and [Ca[sup 2+]][sub i] changes. A concentration- and time-dependent decline in cell shortening was observed during a 20 min period of ET perfusion. At 3% ET, maximal shortening was reduced by 65%. Cell shortening was restored following washout of the ET. In parallel with the depression of contractility, the magnitude of the [Ca[sup 2+]][sub i] transient was also reduced. ET had no significant effect on basal [Ca[sup 2+]][sub i] at concentrations up to 3%. Kinetic parameters of the [Ca[sup 2+]][sub i] transient, including rates of rise and decay were also depressed, although the time to peak was unaffected by ET. These results indicate that ET interferes with Ca[sup 2+] fluxes in the ventricular myocyte in a manner that may contribute to the contractile impairment of cardiac function induced by acute ET exposure in vivo.
- OSTI ID:
- 6992331
- Report Number(s):
- CONF-9202109-; CODEN: FAJOEC
- Journal Information:
- FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 6:1; Conference: American Society for Biochemistry and Molecular Biology and Biophysical Society joint meeting, Houston, TX (United States), 9-13 Feb 1992; ISSN 0892-6638
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALCIUM COMPOUNDS
MEMBRANE TRANSPORT
ETHANOL
BIOLOGICAL EFFECTS
HEART
SENSITIVITY
ACUTE EXPOSURE
CONTRACTION
DOSE-RESPONSE RELATIONSHIPS
TIME DEPENDENCE
ALCOHOLS
ALKALINE EARTH METAL COMPOUNDS
BODY
CARDIOVASCULAR SYSTEM
HYDROXY COMPOUNDS
ORGANIC COMPOUNDS
ORGANS
560300* - Chemicals Metabolism & Toxicology