Simultaneous determination of regional cerebral blood flow and blood--brain glucose transport kinetics in the gerbil.
Cerebral blood flow (CBF) and unidirectional transport of glucose from blood to brain were measured simultaneously in four brain regions of the pentobarbital-anesthetized gerbil. The method consisted of the intravenous injection of a bolus containing [14C]butanol and [3H]glucose, followed by continuous withdrawal of arterial blood and sampling of brain 25 s later. CBF was lowest in the cerebral cortex (50 ml 100 g-1 min-1), highest in the brainstem (89 ml 100 g-1 min-1), and intermediate in the basal ganglia and cerebellum (66 and 69 ml 100 g-1 min-1, respectively). The kinetics of blood-to-brain glucose transport were measured in animals whose blood glucose concentration had been altered by glucose or insulin injections. The half-saturation constant for glucose transport (Km) was similar in all brain regions (7.37-8.14 mM), while the maximal rate of transport (Vmax) was lowest in the cerebral cortex (1.55 mumol g-1 min-1) and significantly higher in the basal ganglia, cerebellum, and brainstem (1.81-2.02 mumol g-1 min-1). These values for CBF and glucose transport are similar to those reported in the literature for other pentobarbital-anesthetized animals. The method provides a simple and rapid technique for determining the effect of ischemia and alterations in CBF on blood-to-brain glucose transport.
D000818:Animals; D001692:Biological Transport; D001786:Blood Glucose / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D005849:Gerbillinae; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008722:Methods
D001786:Blood Glucose; D005947:Glucose