Intracerebroventricular infusion but not bolus injection of vasopressin increases the cerebrospinal fluid pressure in awake rabbits.
The effect of intracerebroventricular infusion or injection of arginine vasopressin (AVP) was examined in awake rabbits with permanent ventricular cannulae. Intracerebroventricular infusion of artificial cerebrospinal fluid (CSF) 43 microliters min-1 containing AVP concentrations exceeding 0.4 ng ml-1, equivalent to an AVP infusion rate of 17.2 pg min-1, caused a dose-dependent increase in intracranial pressure (ICP) of 3 to 5 mmHg after 30-50 min of AVP infusion. Intracerebroventricular bolus injection of equivalent doses of AVP did not provoke changes in ICP. At the end of the experiments cisternal CSF concentrations of AVP were higher after infusion of AVP than after injection of the same amount of AVP. The mean arterial blood pressure increased slightly in the group of animals infused with AVP at rates above 17.2 pg min-1. It is concluded that intracerebroventricular infusion of AVP increases ICP in awake rabbits but the mechanism responsible for the elevation of ICP remains speculative.
Sørensen
P S
PS
University Department of Neurology, Rigshospitalet, Copenhagen, Denmark.
Gyring
J A
JA
D000818:Animals; D001127:Arginine Vasopressin / Q000008:administration & dosage / Q000494:pharmacology*; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D015170:Cerebrospinal Fluid Pressure / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007263:Infusions, Parenteral; D007276:Injections, Intraventricular; D007427:Intracranial Pressure / Q000187:drug effects*; D008297:Male; D011817:Rabbits; D012016:Reference Values; D013997:Time Factors
D001127:Arginine Vasopressin