Effects of acute and chronic ethanol administration on hepatic hemodynamics and hepatic oxygen consumption in awake rats

Background/Aims and Methods: We investigated by effects of acute and chronic ethanol administration on hepatic hemodynamics and hepatic oxygen delivery and consumption in awake rats, using the radiolabeled microsphere technique and measurement of oxygen content in blood. Results: Acute oral and intraarterial ethanol administration produced a significant increase in liver blood flow and hepatic oxygen delivery, but resulted in a significant (25–41%) decrease in hepatic oxygen consumption. These changes lasted up to 5 h after ethanol administration. At 24 h, hepatic oxygen consumption was significantly increased by 33% over control values. During withdrawal in rats fed liquid diets containing alcohol for 6 weeks, hepatic oxygen delivery was maintained at the same level as control pair-fed rats, while hepatic oxygen consumption increased by 28%. Further, in abstinent rats, acute ethanol readministration resulted in a 41% increase in hepatic oxygen delivery but a 32% decrease in hepatic oxygen consumption. Conclusions: These findings demonstrate, in awake animals, a biphasic response of hepatic oxygen consumption following acute ethanol administration and an increase in hepatic oxygen consumption following chronic ethanol intake. Furthermore, acute ethanol treatment reduced hepatic oxygen consumption in spite of an increase in hepatic oxygen delivery.