Altered Glut4 mRNA levels in specific brain areas of hyperglycemic-hyperinsulinemic rats

The insulin sensitive glucose transporter Glut4 is expressed in neurons of the brain among which those of hypothalamic nuclei. It has been proposed th at this transporter might be involved in the hypothalamic glucose-insulin s ensing mechanism and thus in the nervous regulation of metabolism. In order to get further insights into its putative role, Glut4 expression was analy zed by quantitative competitive reverse transcription-polymerase chain reac tion, in hypothalamic nuclei of hyperglycemic-hyperinsulinemic (HG-HI) rats , a model characterized by alteration of the autonomic nervous system activ ity. Glut4 mRNA content was decreased in the lateral hypothalamic area (33% ) and arcuate nucleus (27%) but significantly only in the former. It was un changed in other structures. These results are in favor of an alteration of Glut4 expression by short-term hyperglycemia and hyperinsulinemia that, in turn, could affect autonomic nervous system activity. (C) 2001 Elsevier Sc ience Ireland Ltd. All rights reserved.