Differential regulation of glucokinase and GLUT-2 glucose transporter gene expression in pancreas and liver from neonatal and 16 day old rats.
Glucokinase and GLUT-2 high Km glucose transporter gene expression were studied in pancreas and liver from 2 day old neonatal and 16 day old rats. In pancreas tissue the glucokinase gene was transcribed into a 2.8 kb and a 4.4 kb mRNA species. However, while the 2.8 kb transcript was expressed already in pancreas from 2 day old neonatal rats, distinct expression of the 4.4 kb transcript occurred only in the pancreas from 16 day old rats. GLUT-2 glucose transporter was expressed already in the pancreas from 2 day old neonatal rats, albeit to a lesser extent than in the pancreas from 16 day old rats. Liver glucokinase gene was not expressed in 2 day old neonatal rats but in 16 day old neonatal rats, whereas the GLUT-2 glucose transporter gene was expressed both in the liver from 2 day old neonatal and 16 day old rats. The differences between glucokinase gene expression in neonatal pancreas and neonatal liver provide an indication for a different function of this enzyme in the two tissues. The immature insulin secretory response to glucose in neonatal pancreas may be related to a deficient glucokinase and probably also to a reduced GLUT-2 glucose transporter gene expression.
Tiedge
M
M
Institute of Clinical Biochemistry, Hannover Medical School, Germany.
Lenzen
S
S
D000375:Aging / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D005941:Glucokinase / Q000235:genetics*; D051273:Glucose Transporter Type 2; D007515:Islets of Langerhans / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D014158:Transcription, Genetic
D051273:Glucose Transporter Type 2; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D005941:Glucokinase