Direct effects of ethanol on heart function was examined using the Langendorff preparation. The heart was excised from male Wistar rats and perfused with the modified Krebs-Henseleit's solution through the aorta. After a stabilizing period of 15
min. 10
or 25%(V/V) ethanol was added to the perfusate. Heart rate. intraventricular pressure, rate of change in intraventricular pressure which reflects the ventricular contractility and atria natriuretic peptide (ANP) concentration were measured at 1,
5
and
10 min after addition of ethanol. Ethanol decreased the intraventricular pressure, ventricular contractility change in intraventricular pressure and the coronary flow. These responses were ethanol-dose dependent. Secretion of ANP was increased
during
the first minute of ethanol administration but was recovered to the preinfusion level, thereafter, Secretion of ANP was inversely related to the coronary flow: ANP secretion =868.1 -46.1×Flow(r= -0.53, P<0.001). At 10 min of ethanol perfusion,
intraventricular pressure, rate of pressure change, and flow in ethanol group were significantly different from control.
Above results suggest that ethanol depresses the cardiac function, but increases the concentration of ANP only immediately after ethanol infusion.
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