Plasma arginine vasopressin response to oral, gastric, and intravenous water load in patients with cirrhosis.
OBJECTIVE
Hepatic osmoreceptors are sensitive to changes in portal blood osmolality and cause variations in plasma antidiuretic hormone and water diuresis, which prevent major systemic osmotic changes. Insensitivity of hepatic osmoreceptors might contribute to maintaining increased plasma levels of antidiuretic hormone and negative free water clearance after oral hydration in some cirrhotic patients.


METHODS
We measured free water clearance and plasma arginine vasopressin levels in basal conditions and after oral, intravenous, and intragastric water overload in control subjects (group I) and patients with cirrhosis (some with a positive [group II] and some a negative [group III] free water clearance).


RESULTS
In groups I and II, no significant differences in plasma arginine vasopressin levels were found regardless of the route used for hydration. In group III, plasma levels were significantly higher between 0 and 75 minutes after intragastric hydration than after oral or intravenous hydration. No significant changes in plasma osmolality were detected between minute 0 and 20 after the end of oral or intragastric hydration, although plasma arginine vasopressin decreased significantly only 5 minutes after the oral hydration. Group III patients showed evidence of autonomic neuropathy. However, this dysfunction was unrelated to the insensitivity to gastric hydration.


CONCLUSIONS
Hepatic osmoreceptors seem to be disturbed in some cirrhotic patients, although this dysfunction may be compensated for by normally functioning oropharyngeal and hypothalamic osmoreceptors.
Castellano
G
G
Gastroenterology Unit, Hospital Doce de Octubre, School of Medicine, Universidad Complutense, Madrid, Spain.
Solis-Herruzo
J A
JA
Gonzalez
A
A
Morillas
J D
JD
Moreno
D
D
Muñoz
T
T
Larrodera
L
L
D000284:Administration, Oral; D001127:Arginine Vasopressin / Q000097:blood*; D001341:Autonomic Nervous System / Q000503:physiopathology; D004231:Diuresis; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007441:Intubation, Gastrointestinal; D008103:Liver Cirrhosis / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D014867:Water / Q000008:administration & dosage* / Q000494:pharmacology
D014867:Water; D001127:Arginine Vasopressin