| Autor: |
Christopher, Michael, Rantzau, Christian, Zhi-Ping Chen, Snow, Rodney, Kemp, Bruce, Alford, Frank P. |
| Předmět: |
|
| Zdroj: |
American Journal of Physiology: Endocrinology & Metabolism; Nov2006, Vol. 291, pE1131-E1140, 10p |
| Abstrakt: |
AMPK plays a central role in influencing fuel usage and selection. The aim of this study was to analyze the impact of low-dose AMP analog 5-aminoimidazole-4- carboxamide-1-β-D-ribosyl monophosphate (ZMP) on whole body glucose turnover and skeletal muscle (SkM) glucose metabolism. Dogs were restudied after prior 48-h fatty acid oxidation (FAox) blockade by methylpalmoxirate (MP; 5 × 12 hourly 10 mg/kg doses). During the basal equilibrium period (0-150 min), fasting dogs (n = 8) were infused with [3-³H]glucose followed by either 2-h saline or AICAR (1.5-2.0 mg·kg-1·min-1) infusions. SkM was biopsied at completion of each study. On a separate day, the same protocol was undertaken after 48-h in vivo FAox blockade. The AICAR and ALCAR + MP studies were repeated in three chronic alloxan-diabetic dogs. AICAR produced a transient fall in plasma glucose and increase in insulin and a small decline in free fatty acid (FFA). Parallel increases in hepatic glucose production (HGP), glucose disappearance (Rd tissue) and glycolytic flux (GF) occurred, whereas metabolic clearance rate of glucose (MCRg) did not change significantly. Intracellular SkM glucose, glucose 6-phosphate, and glycogen were un- changed. Acetyl-CoA carboxylase (ACC∼pSer221) increased by 50%. In the AICAR + MP studies, the metabolic responses were modified: the glucose was lower over 120 min, only minor changes occurred with insulin and FFA, and HGP and Rd tissue responses were markedly attenuated, but MCRg and GF increased significantly. SkM substrates were unchanged, but ACC∼pSer221 rose by 80%. Thus low-dose AICAR leads to increases in HOP and SkM glucose uptake, which are modified by prior FAox blockade. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
