Stroke, Vol 20, 1545-1552, Copyright © 1989 by American Heart Association
GL Clifton, WC Taft, RE Blair, SC Choi and RJ DeLorenzo
We looked at FiO2, choice of anesthetic, nutritional status, and body
temperature in a gerbil model of forebrain ischemia to determine their
effect on data interpretation, ischemic outcome, and extent of
pharmacologic protection. We subjected 484 gerbils to 5 minutes of
forebrain ischemia under different experimental conditions. The gerbils
were anesthetized with 3% halothane and inspired 21% O2, 37% O2 and 60%
N2O, or 97% O2. Six groups of gerbils pretreated with 200 mg/kg phenytoin
or 2 ml/kg polyethylene glycol (vehicle) underwent ischemia in the fasted
or fed state. Three groups of gerbils receiving no pretreatment underwent
ischemia with rectal temperatures of 32-33 degrees C, 34-35 degrees C, or
37 degrees C. We counted intact neurons in the CA1 hippocampal sector in
brains fixed on Day 7 after ischemia. t tests of square-root-transformed
cell counts were used to assess the effect of hypothermia, and analysis of
variance of the transformed data was used to test for the effects of
phenytoin, FiO2, and nutritional status. Phenytoin pretreatment provided
significant protection from CA1 neuron loss in all groups tested (p less
than 0.001), but the degree of protection varied from 20% to 44%. In spite
of significantly higher serum glucose concentrations in fed than in fasted
gerbils (173 and 118 mg/dl, respectively), we found no significant effect
of nutritional status upon neuron loss in phenytoin- or vehicle-pretreated
gerbils. An FiO2 of 21% significantly decreased the number of viable
neurons in both vehicle- and phenytoin-pretreated groups (p less than
0.03), despite the lack of an effect of hypoxemia on arterial blood
gases.(ABSTRACT TRUNCATED AT 250 WORDS)
ARTICLES
Conditions for pharmacologic evaluation in the gerbil model of forebrain ischemia
Department of Surgery, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0677.