AJP - Regulatory, Integrative and Comparative Physiology, Vol 238, Issue 5 340-R345, Copyright © 1980 by American Physiological Society
Drinking and vasopressin release during ventricular infusions of hypertonic solutions
T. N. Thrasher, R. G. Jones, L. C. Keil, C. J. Brown and D. J. Ramsay
Six dogs were administered third ventricular infusions of artificial
cerebrospinal fluid (CSF) (292 mosmol/l) alone or artificial CSF to which
neither NaCl, sucrose, glucose, or urea was added to yield a final osmolar
concentration of 500 mosmol/l. The volume of water drunk during 45 min of
infusion was measured and blood was sampled for determination of plasma
vasopressin concentration at 15-min intervals. Artificial CSF made
hypertonic by addition of NaCl or sucrose stimulated water intakes of 9.0
+/- 3.2 ml/kg (mean +/- SE) and 7.3 +/- 3.7 ml/kg, respectively. There was
no statistical difference in the amounts drunk and the latencies. In
contrast, artificial CSF containing glucose, urea, or artificial CSF alone
were without effect. Plasma vasopressin concentration increased
significantly in response to intraventricular NaCl and sucrose but was not
affected by glucose, urea, or artificial CSF alone. These data are
compatible with an osmoreceptor mechanism mediating drinking and
vasopressin release.
