AJP - Regulatory, Integrative and Comparative Physiology, Vol 245, Issue 4 541-R548, Copyright © 1983 by American Physiological Society
Vasopressin in blood and third ventricle CSF of dogs in chronic experiments
C. Simon-Oppermann, D. Gray, E. Szczepanska-Sadowska and E. Simon
A device for chronic implantation was developed that allowed sampling of
cerebrospinal fluid (CSF) from the anterior part of the third cerebral
ventricle (A3V) of dogs in repeated experiments for up to 4 mo.
Osmolalities, electrolyte concentrations, and concentrations of arginine
vasopressin (AVP) measured with a radioimmunoassay were determined in
repeated experiments on the chronically prepared animals under conditions
of normal hydration, both in the conscious state and during inhalation
anesthesia. In conscious dogs, AVP concentrations in plasma and CSF were
3.3 +/- 0.4 and 21.8 +/- 2.5 pg X ml-1, respectively. During anesthesia
without surgical interference, the AVP concentrations in plasma and CSF
were increased twofold above the levels obtained in conscious dogs. During
the time of observation (180 min) all measured parameters remained
constant. The AVP concentrations in plasma and CSF samples collected during
the surgical procedure of device implantation were about 10-fold higher
than in the samples collected during the conscious state. Thus, in each
experimental condition, AVP concentration in the CSF collected from the A3V
was consistently higher than that in the simultaneously collected blood
samples.
