- Long-chain acylcarnitines decrease the phosphorylation of the insulin receptor at tyr1151 through a ptp1b-dependent mechanism
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The accumulation of lipid intermediates may interfere with energy metabolism pathways and regulate cellular energy supplies. As increased levels of long-chain acylcarnitines have been linked to insulin resistance, we investigated the effects of long-chain acylcarnitines on key components of the insulin signalling pathway. We discovered that palmitoylcarnitine induces dephosphorylation of the insulin receptor (InsR) through increased activity of protein tyrosine phosphatase 1B (PTP1B). Palmitoylcarnitine suppresses protein kinase B (Akt) phosphorylation at Ser473, and this effect is not alleviated by the inhibition of PTP1B by the insulin sensitizer bis-(maltolato)-oxovanadium (IV). This result indicates that palmitoylcarnitine affects Akt activity independently of the InsR phosphorylation level. Inhibition of protein kinase C and protein phosphatase 2A does not affect the palmitoylcarnitine-mediated inhibition of Akt Ser473 phosphorylation. Additionally, palmitoylcarnitine markedly stimulates insulin release by suppressing Akt Ser473 phosphorylation in insulin-secreting RIN5F cells. In conclusion, long-chain acylcarnitines activate PTP1B and decrease InsR Tyr1151 phosphorylation and Akt Ser473 phosphorylation, thus limiting the cellular response to insulin stimulation.
- Vilks, Karlis,Videja, Melita,Makrecka-Kuka, Marina,Katkevics, Martins,Sevostjanovs, Eduards,Grandane, Aiga,Dambrova, Maija,Liepinsh, Edgars
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- NOVEL CRYSTALLINE FORMS
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Preparation and characterization of novel forms of (1-hydroxy-2-imidazol-1-yl-1-phosphono-ethyl) phosphonic acid, suitable for pharmaceutical compositions in drug delivery systems for humans.
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- Process for the production of a fatty acid/carnitine derivative
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The present invention discloses a process for the production of a fatty acid/L-carnitine.HCl derivative, whereby the educts are reacted in the presence of mono-chloroacetic acid.
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Page/Page column 2
(2010/08/18)
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- TOPICAL SLIMMING PREPARATION AND A COSMETIC CONTAINING A CARNITINE DERIVATIVE
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The invention provides a slimming skin external preparation and a cosmetic that contain a carnitine derivative having excellent skin affinity and percutaneous absorption properties and capable of enhancing the fat metabolism, and that can treat, reduce
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Page/Page column 74; 75
(2008/06/13)
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