The brain response to 2-deoxy glucose is blocked by a glial drug.
Two brain regions - the basomedial hypothalamus and area postrema (AP) - react to changes in circulating glucose levels by altering feeding behavior and the secretion of pituitary and non-pituitary hormones. The precise identity of cells responding to glucose in these regions is uncertain. The recent detection of high-capacity glucose transporter proteins in astrocytes in these areas has suggested that astrocytes may play a role in glucose sensing by the brain. To test this hypothesis, rats were injected with either saline or methionine sulfoximine (MS), a compound that produces alterations in carbohydrate and glutamate metabolism in astrocytes. Eighteen hours later, rats were injected with either saline or 2-deoxy glucose (2-DG) and brain sections were stained to demonstrate 2-DG-activated neurons immunoreactive for Fos protein. MS-treated rats showed a 70% reduction in numbers of Fos+ neurons in the AP region (p<0.05). Also, specialized, Gomori+ astrocytes were particularly abundant in both glucose sensitive regions and showed a distribution identical to that reported for high-capacity glucose transporter proteins. These data suggest that specialized astrocytes influence the glucose-sensing function of the brain.
Young
J K
JK
Department of Anatomy, Howard University College of Medicine, 520 W. Street NW, Washington DC 20059, USA. jyoung@fac.howard.edu
Baker
J H
JH
Montes
M I
MI
D000818:Animals; D001253:Astrocytes / Q000737:chemistry / Q000187:drug effects; D001786:Blood Glucose / Q000187:drug effects; D001921:Brain / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D003847:Deoxyglucose / Q000097:blood / Q000494:pharmacology*; D005260:Female; D007150:Immunohistochemistry; D008717:Methionine Sulfoximine / Q000494:pharmacology*; D009457:Neuroglia / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D009474:Neurons / Q000737:chemistry / Q000187:drug effects; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
D001786:Blood Glucose; D016760:Proto-Oncogene Proteins c-fos; D008717:Methionine Sulfoximine; D003847:Deoxyglucose