Palmitoyl-L-carnitine-d9 is intended for use as an internal standard for the quantification of palmitoyl-L-carnitine by GC- or LC-MS. Palmitoyl-L-carnitine is a long-chain acylcarnitine and an isomer of palmitoyl-DL-carnitine and palmitoyl-D-carnitine .1 Palmitoyl-L-carnitine is transported into mitochondria via carnitine palmitoyl transferase II to deliver palmitate for fatty acid oxidation and energy production.2 It inhibits lecithin:cholesterol acyltransferase activity in isolated rat, but not human, plasma when used at a concentration of 500 µM.3 Serum and hepatic levels of palmitoyl-L-carnitine are increased in mice during cold exposure, and it is taken up by brown adipose tissue.4 Palmitoyl-L-carnitine also protects against age-induced cold sensitivity in mice.
References:
[1]. Bezaire, V., Bruce, C.R., Heigenhauser, G.J.F., et al.Identification of fatty acid translocase on human skeletal muscle mitochondrial membranes: Essential role in fatty acid oxidationAm. J. Physiol. Endocrinol. Metab.290(3)E509-E515(2006).
[2]. El-Hayek, R., Valdivia, C., Valdivia, H.H., et al.Activation of the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum by palmitoyl carnitineBiophys. J.65(2)779-789(1993).
[3]. Bell, F.P.Carnitine esters: Novel inhibitors of plasma lecithin: Cholesterol acyltransferase in experimental animals but not in man (Homo sapiens)Int. J. Biochem.15(2)133-136(1983).
[4]. Simcox, J., Geoghegan, G., Maschek, J.A., et al.Global analysis of plasma lipids identifies liver-derived acylcarnitines as a fuel source for brown fat thermogenesisCell Metab.26(3)509-522(2017).