Alterations of epinephrine-induced gluconeogenesis in aging
Experimental & Molecular Medicine
;
: 334-340, 2009.
Article
in English
| WPRIM
| ID: wpr-136586
ABSTRACT
The effects of glucagon and epinephrine on gluconeogenesis in young (4 month) and old (24 month) Fisher 344 rat hepatocytes were compared. In contrast to glucagon, which had a similar effect on gluconeogenesis in both young and old cells, epinephrine caused a smaller increase in gluconeogenesis in old rat hepatocytes than in young hepatocytes. beta2 adrenergic receptor (beta2-AR) expression slightly decreased in aged rat liver, and there were differences between young and old hepatocytes in their patterns of G protein coupled receptor kinases, which are involved in the activation of beta2-AR receptor signal desensitization. The major isoform of the kinase changed from GRK2 to GRK3 and the expression of beta-arrestin, which is recruited by the phosphorylated beta2-AR for internalization and degradation, increased in aged rat liver. GRK3 overexpression also decreased the glucose output from young rat hepatocytes. We conclude that an age-associated reduction in epinephrine-induced gluconeogenesis occurs through the epinephrine receptor desensitizing system.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Phosphorylation
/
Rats, Inbred F344
/
Aging
/
Glucagon
/
Epinephrine
/
Receptors, Adrenergic, beta-2
/
Adrenergic beta-Agonists
/
G-Protein-Coupled Receptor Kinase 2
/
G-Protein-Coupled Receptor Kinase 3
/
Gluconeogenesis
Type of study:
Prognostic study
Limits:
Animals
Language:
English
Journal:
Experimental & Molecular Medicine
Year:
2009
Type:
Article
Similar
MEDLINE
...
LILACS
LIS