Reduced adrenergic sensitivity in vivo in acute ethanol-fed rats

Prior studies indicate ethanol feeding induces adrenergic subsensitivity in vitro, as measured by cyclic adenosine monophosphate (cAMP) response of tissues to norepinephrine (NE). In this report we show acute ethanol feeding induces a depressed level of adrenergic sensitivity in vivo, as measured by plasma cAMP response to isoproterenol. Two hours after intragastric feeding of ethanol (6 gm/kg) to rats, there was a decrease in plasma cAMP response to intravenous isoproterenol, compared to dextrose controls. This decrease was the same in animals with blood ethanol levels averaging 68 mg/dl or 193 mg/dl. This data is consistent with the hypothesis that ethanol induces adrenergic subsensitivity.