Induced changes in intracranial pressure in the anesthetized rat and rabbit.

Intracranial pressure (ICP) was measured continuously in anesthetized, free-breathing, adult, male Sprague-Dawley rats and New Zealand White rabbits by means of a subarachnoid screw technique. The effect upon ICP of changing the volumes within the cranium by infusion of artificial cerebrospinal fluid into the lateral cerebral ventricle at various rates was examined. Results obtained demonstrated some of the elastic and compensatory aspects of cerebrospinal fluid dynamics. The effects upon ICP of the intravenous administration of urea, mannitol, acetazolamide, dimethyl sulfoxide, norepinephrine, epinephrine, isoproterenol, nitroglycerin, papaverine, histamine, angiotension II, pitressin, sodium nitroprusside, diazoxide, lidocaine, sodium pentobarbitone, as well as inhalation of amyl nitrate and carbon dioxide were examined in anesthetized rats. The effect upon ICP of the intravenous infusion of urea, as well as the bolus intravenous administration of epinephrine and pitressin was examined in the anesthetized rabbit. Results obtained from these animals demonstrate the action of these experimental interventions upon ICP as measured by means of the subarachnoid screw technique.