Selective tonic inhibition of G-6-Pase catalytic subunit, but not G-6-P transporter, gene expression by insulin in vivo.
Am J Physiol Endocrinol Metab
; 281(4): E713-25, 2001 Oct.
Article
en En
| MEDLINE
| ID: mdl-11551847
ABSTRACT
The regulation of glucose-6-phosphatase (G-6-Pase) catalytic subunit and glucose 6-phosphate (G-6-P) transporter gene expression by insulin in conscious dogs in vivo and in tissue culture cells in situ were compared. In pancreatic-clamped, euglycemic conscious dogs, a 5-h period of hypoinsulinemia led to a marked increase in hepatic G-6-Pase catalytic subunit mRNA; however, G-6-P transporter mRNA was unchanged. In contrast, a 5-h period of hyperinsulinemia resulted in a suppression of both G-6-Pase catalytic subunit and G-6-P transporter gene expression. Similarly, insulin suppressed G-6-Pase catalytic subunit and G-6-P transporter gene expression in H4IIE hepatoma cells. However, the magnitude of the insulin effect was much greater on G-6-Pase catalytic subunit gene expression and was manifested more rapidly. Furthermore, cAMP stimulated G-6-Pase catalytic subunit expression in H4IIE cells and in primary hepatocytes but had no effect on G-6-P transporter expression. These results suggest that the relative control strengths of the G-6-Pase catalytic subunit and G-6-P transporter in the G-6-Pase reaction are likely to vary depending on the in vivo environment.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Transporte de Monosacáridos
/
Regulación de la Expresión Génica
/
Antiportadores
/
Glucosa-6-Fosfatasa
/
Insulina
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Am J Physiol Endocrinol Metab
Asunto de la revista:
ENDOCRINOLOGIA
/
FISIOLOGIA
/
METABOLISMO
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos