title: Induction of brain glucose uptake by a factor secreted into cerebrospinal fluid.
abstract: It is well established that the carotid body receptors (CBR), at the bifurcation of the carotid artery, inform the brain of changes in the concentration of CO(2) and O(2) in arterial blood. More recent work suggests that these receptors are also extremely sensitive to blood glucose levels suggesting that they may play an important role as sensors of blood components important for brain energy metabolism. Much less is known about changes in brain glucose metabolism in response to CBR activation. Here we show that 2-8 min after local injection of sodium cyanide (NaCN) into the CBR or after electrical stimulation of the carotid sinus nerve in dogs and rats, brain glucose uptake increased fourfold. Cerebrospinal fluids (CSF) transferred from dogs, 2-8 min after CBR stimulation, into the cisterna magna of non-stimulated dogs or rats induced a similar increase in brain glucose uptake. CSF from stimulated dogs was also active when injected intravenously in anesthetized or awake rats. The activity was destroyed when the stimulated CSF was heated to 100 degrees C or treated with trypsin. We conclude that a peptide important for brain glucose regulation appears in the CSF shortly after CBR stimulation.
authors.affiliation: Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, 28045 Colima, Mexico.
authors.forename: Ramón
authors.initials: R
authors.lastname: Alvarez-Buylla
authors.forename: Alberto
authors.initials: A
authors.lastname: Huberman
authors.forename: Sergio
authors.initials: S
authors.lastname: Montero
authors.forename: Monica
authors.initials: M
authors.lastname: Lemus
authors.forename: Victoria
authors.initials: V
authors.lastname: Valles
authors.forename: Elena Roces
authors.initials: ER
authors.lastname: de Alvarez-Buylla
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002344:Carotid Body / Q000187:drug effects / Q000378:metabolism*; D004285:Dogs; D004558:Electric Stimulation / Q000379:methods; D005947:Glucose / Q000134:cerebrospinal fluid* / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012966:Sodium Cyanide / Q000494:pharmacology
chemical_list: D005947:Glucose; D012966:Sodium Cyanide