Effects of insulin on hexose transport across blood-brain barrier in normoglycemia

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5301089

Namba, H; Lucignani, G; Nehlig, A; Patlak, C; Pettigrew, K; Kennedy, C; Sokoloff, L

The effects of insulin on 3-O-(/sup 14/C) methylglucose transport across the blood-brain barrier (BBB) were studied in conscious rats under steady-state normoglycemic conditions. The (/sup 14/C)methylglucose was infused intravenously at a constant rate, and animals were killed at various times between 5 and 30 min after the initiation of the infusion. The time course of the arterial plasma concentration of (/sup 14/C)methylglucose was determined in timed arterial blood samples taken during the infusion. Local cerebral tissue concentrations of (/sup 14/C)methylglucose at the time of killing were determined by quantitative autoradiography of brain sections. The rate constants for inward and outward transport of (/sup 14/C)methylglucose across the BBB, K/sub 1/, and k/sub 2/, respectively, were estimated by a least-squares, best-fit of a kinetic equation to the measured time courses of plasma and tissue concentrations. The equilibrium distribution ration, K/sub 1//k/sub 2/, for (/sup 14/C)methylglucose in brain increased by approx. 10-11% in the hyperinsulinemic animals. Because 3-O-(/sup 14/C)methylglucose shares the same carrier that transports glucose and other hexoses across the BBB, these results suggest that hyperinsulinemia decreases the rate constants for transport but increases the distribution space for hexoses in brain. These effects are, however, quite small and are probably minor or negligible when compared with the major effects of insulin in other tissues.

• Research Organization: Dept. of Health and Human Services, Bethesda, MD
• OSTI ID: 5301089
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:3; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALDEHYDES
ANIMALS
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BLOOD PRESSURE
BLOOD-BRAIN BARRIER
BODY
BRAIN
CARBOHYDRATES
CARBON 14 COMPOUNDS
CENTRAL NERVOUS SYSTEM
GLUCOSE
HEXOSES
HORMONES
INSULIN
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
MONOSACCHARIDES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
RATS
REACTION KINETICS
RODENTS
SACCHARIDES
VERTEBRATES