Pentobarbital anesthesia reduces blood-brain glucose transfer in the rat.
Pentobarbital anesthesia (40 mg kg-1) was accompanied by a 50% decrease of blood flow and a 40% decrease of unidirectional blood-brain glucose transfer in the parietal cortex of the rat brain. The correlation was explained by a decrease of the number of perfused capillaries. The maximal transport capacity, Tmax, decreased from 409 to 235 mumol 100 g-1 min-1 and the half-saturation constant, Km, from 8.8 to 4.9 mM. At 8.3-8.7 mM-glucose in arterial plasma, the transfer constant (clearance) for unidirectional blood-brain transfer decreased from 0.195 +/- 0.011 in awake rats to 0.132 +/- 0.005 ml g-1 min-1 in anesthetized rats. Half of the decrease was due to less complete diffusion-limitation of glucose uptake at the low plasma flow rate in brain, the other half to the decreased Tmax.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001812:Blood-Brain Barrier / Q000187:drug effects*; D002540:Cerebral Cortex / Q000098:blood supply; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects
D001786:Blood Glucose; D010424:Pentobarbital; D005947:Glucose