Downregulation of AMPK accompanies leucine- and glucose-induced increases in protein synthesis and insulin resistance in rat skeletal muscle.

Objective: Branched-chain amino acids, such as leucine and glucose, stimulate protein synthesis and increase the phosphorylation and activity of the mammalian target of rapamycin (mTOR) and its downstream target p70S6 kinase (p70S6K). We examined in skeletal muscle whether the effects of leucine and glucose on these parameters and on insulin resistance are mediated by the fuel-sensing enzyme AMP-activated protein kinase (AMPK).

Research Design And Methods: Rat extensor digitorum longus (EDL) muscle was incubated with different concentrations of leucine and glucose with or without AMPK activators.

Anti-growth effect of 1,25-dihydroxyvitamin D3-3-bromoacetate alone or in combination with 5-amino-imidazole-4-carboxamide-1-beta-4-ribofuranoside in pancreatic cancer cells.

1,25-Dihydroxyvitamin D(3)-3-bromoacetate (1,25(OH)(2)D(3)-3-BE) is a vitamin D receptor-alkylating derivative of 1,25(OH)(2)D(3). The strong dose-dependent antiproliferative and apoptotic effects of this compound in androgen-sensitive and androgen-insensitive prostate cancer cells have been reported. In this communication, it is reported that 1,25(OH)(2)D(3)-3-BE strongly inhibits the growth of several pancreatic cancer cell lines.

Hypothalamic fatty acid metabolism mediates the orexigenic action of ghrelin.

Current evidence suggests that hypothalamic fatty acid metabolism may play a role in regulating food intake; however, confirmation that it is a physiologically relevant regulatory system of feeding is still incomplete. Here, we use pharmacological and genetic approaches to demonstrate that the physiological orexigenic response to ghrelin involves specific inhibition of fatty acid biosynthesis induced by AMP-activated protein kinase (AMPK) resulting in decreased hypothalamic levels of malonyl-CoA and increased carnitine palmitoyltransferase 1 (CPT1) activity. In addition, we also demonstrate that fasting downregulates fatty acid synthase (FAS) in a region-specific manner and that this effect is mediated by an AMPK and ghrelin-dependent mechanisms.