The Measurement of Cerebral Blood Flow in the Rat

Abstract

Cerebral blood flow (CBF) was determined in the rat under 70% nitrous oxide anesthesia and pentobarbital anesthesia. The application of the Fick principle technique of Kety et al. was modified utilizing 123 Xe infused intravenously steadily for 30 seconds, at which time the animal was decapitated and the head frozen in liquid nitrogen. A prior femoral artery to femoral vein shunt was led through a polyethylene catheter of 0.13 ml volume. This catheter passed as a coil in a Nal crystal well-counter with the arterial 133 Xe concentration curve recorded by a ratemeter-recordcr system. The results of the hemispheric blood flow (HBF) were: under 70% nitrous oxide anesthesia in normocapnia (Paco, 38 mm Hg), 86 ± 15 ml/100 gm per minute; with hypocapnia (Paco, 20 mm Hg), 40 ± 5 ml/100 gm per minute; with hypercapnia (Paco, 63 mm Hg), 187 ± 10 ml/100 gm per minute; and with pentobarbital anesthesia (Paco, 38 mm Hg), 41 ± 8 ml/100 gm per minute.