AJP - Regulatory, Integrative and Comparative Physiology, Vol 242, Issue 5 522-R527, Copyright © 1982 by American Physiological Society
Effect of ethanol ingestion on plasma vasopressin and water balance in humans
G. Eisenhofer and R. H. Johnson
The effects of 75 ml ethanol ingested over 60 min on plasma osmolality
(Posmol) and plasma vasopressin (PAVP) in four normal subjects were
studied. In the 1st h of the investigation PAVP fell, then rose, even
though plasma ethanol levels were still rising. The rise in PAVP was
preceded by a rise in Posmol corrected for the influence of ethanol. The
fall in PAVP was followed by an increase in free water clearance and a
decrease in urine osmolality, while the later rise in PAVP was followed by
a decrease in free water clearance (CH2O) and a rise in urine osmolality.
The relationship between PAVP and Posmol was then studied during
intravenous (iv) hypertonic saline infusion in five subjects. The results
were compared with those from a second infusion in the same subjects after
ingestion of ethanol (0.5 ml/kg). Ethanol reduced vasopressin release in
response to iv hypertonic saline infusion, and this correlated with a
reduced decrease in CH2O. We conclude that ethanol inhibits PAVP release by
decreasing the response of the osmosodium receptors to changes in plasma
tonicity.
