title: Feeding enhances extracellular lactate of local origin in the rostromedial hypothalamus but not in the cerebellum.
abstract: The use of brain microdialysis together with chronic vascular catheterization allowed us to assay extracellular fluid lactate (ECFL) in both the ventromedial-paraventricular (VMH-PVN) area of the hypothalamus and the cerebellum, in parallel with measures of plasma levels, and in relation to food intake. A 45 min scheduled meal increased VMH-PVN ECFL by 28%. This increase was not observed in the cerebellum. The prandial increase in plasma glucose (43%, from 4.74 to 6.77 mM) and lactate (84%, from 0.83 to 1.53 mM) showed a different temporal pattern and lasted longer than that of the ECFL. Glucose delivery by reverse dialysis for 45 min into the VMH-PVN area increased ECFL by 49%. When local glucose utilization was prevented by reverse dialysis-delivered 2-deoxy-d-glucose (2-DG), not only did VMH-PVN ECFL drop, but the feed-related increase in ECFL was blocked without affecting the normal rise in plasma glucose and in lactate. These results indicate that meal-related ECFL production and variations are independent of circulating lactate, but may depend on substrate availability in these hypothalamic structures.
authors.affiliation: Institut Européen des Sciences du Goût et des Comportements Alimentaires, C.N.R.S. U.P.R. 9054, Neurobiologie, Université de Bourgogne, 15 rue Hugues Picardet 21000, Dijon, France. goucham@cesg.cnrs.fr
authors.forename: A Y
authors.initials: AY
authors.lastname: Goucham
authors.forename: S
authors.initials: S
authors.lastname: Nicolaïdis
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002531:Cerebellum / Q000378:metabolism*; D003847:Deoxyglucose / Q000494:pharmacology; D004435:Eating / Q000502:physiology*; D005110:Extracellular Space / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism; D019518:Postprandial Period / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism*
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D003847:Deoxyglucose; D005947:Glucose