TY - JOUR

T1 - The Kety-Schmidt technique for repeated measurements of global cerebral blood flow and metabolism in the conscious rat

AU - Linde, R

AU - Schmalbruch, I K

AU - Paulson, O B

AU - Madsen, Peter Lund

PY - 1999/4

Y1 - 1999/4

N2 - Cerebral activation will increase cerebral blood flow (CBF) and cerebral glucose uptake (CMRglc) more than it increases cerebral uptake of oxygen (CMR(O2)). To study this phenomenon, we present an application of the Kety-Schmidt technique that enables repetitive simultaneous determination of CBF, CMR(O2), CMRglc and CMRlac on awake, non-stressed animals. After constant intravenous infusion with 133Xenon, tracer infusion is terminated, and systemic arterial blood and cerebral venous blood are continuously withdrawn for 9 min. In this paper, we evaluate if the assumptions applied with the Kety-Schmidt technique are fulfilled with our application of the method. When measured twice in the same animal, the intra-individual variation for CBF, CMR(O2), and CMRglc were 10% (SD: 25%), 8% (SD: 25%), and 9% (SD: 28%), respectively. In the awake rat the values obtained for CBF, CMR(O2) and CMRglc were 106 mL [100 g](-1) min(-1), 374 micromole [100 g](-1) min(-1) and 66 micromole [100 g](-1) min(-1), respectively. The glucose taken up by the brain during wakefulness was fully accounted for by oxidation and cerebral lactate efflux. Anaesthesia with pentobarbital induced a uniform reduction of cerebral blood flow and metabolism by approximately 40%. During halothane anaesthesia CBF and CMRglc increased by approximately 50%, while CMR(O2) was unchanged.

AB - Cerebral activation will increase cerebral blood flow (CBF) and cerebral glucose uptake (CMRglc) more than it increases cerebral uptake of oxygen (CMR(O2)). To study this phenomenon, we present an application of the Kety-Schmidt technique that enables repetitive simultaneous determination of CBF, CMR(O2), CMRglc and CMRlac on awake, non-stressed animals. After constant intravenous infusion with 133Xenon, tracer infusion is terminated, and systemic arterial blood and cerebral venous blood are continuously withdrawn for 9 min. In this paper, we evaluate if the assumptions applied with the Kety-Schmidt technique are fulfilled with our application of the method. When measured twice in the same animal, the intra-individual variation for CBF, CMR(O2), and CMRglc were 10% (SD: 25%), 8% (SD: 25%), and 9% (SD: 28%), respectively. In the awake rat the values obtained for CBF, CMR(O2) and CMRglc were 106 mL [100 g](-1) min(-1), 374 micromole [100 g](-1) min(-1) and 66 micromole [100 g](-1) min(-1), respectively. The glucose taken up by the brain during wakefulness was fully accounted for by oxidation and cerebral lactate efflux. Anaesthesia with pentobarbital induced a uniform reduction of cerebral blood flow and metabolism by approximately 40%. During halothane anaesthesia CBF and CMRglc increased by approximately 50%, while CMR(O2) was unchanged.

KW - Animals

KW - Brain/blood supply

KW - Cerebral Arteries/physiology

KW - Cerebral Veins/physiology

KW - Cerebrovascular Circulation/physiology

KW - Glucose/metabolism

KW - Infusions, Intravenous

KW - Male

KW - Oxygen Consumption/physiology

KW - Rats

KW - Rats, Sprague-Dawley

KW - Reproducibility of Results

KW - Wakefulness

KW - Xenon Radioisotopes

U2 - 10.1046/j.1365-201x.1999.00522.x

DO - 10.1046/j.1365-201x.1999.00522.x

M3 - Journal article

C2 - 10350234

VL - 165

SP - 395

EP - 401

JO - Acta Physiologica Scandinavica

JF - Acta Physiologica Scandinavica

SN - 0001-6772

IS - 4

ER -