TY - JOUR
T1 - The Effects of Long-or Medium-Chain Fat Diets on Glucose Toleance and Myocellular Content of Lipid Intermediates in Rats
AU - de Vogel-van den Bosch, H.M.
AU - Hoeks, J.
AU - Timmers, S.
AU - Houten, S.M.
AU - Dijk, P.J.
AU - Boon, W.P.C.
AU - van Beurden, D.
AU - Schaart, G.
AU - Kersten, A.H.
AU - Voshol, P.J.
AU - Wanders, R.J.A.
AU - Hesselink, M.K.
AU - Schrauwen, P.
PY - 2011
Y1 - 2011
N2 - Accumulation of triacylglycerols (TAGs) and acylcarnitines in skeletal muscle upon high-fat (HF) feeding is the resultant of fatty acid uptake and oxidation and is associated with insulin resistance. As medium-chain fatty acids (MCFAs) are preferentially ß-oxidized over long-chain fatty acids, we examined the effects of medium-chain TAGs (MCTs) and long-chain TAGs (LCTs) on muscle lipid storage and whole-body glucose tolerance. Rats fed a low-fat (LF), HFLCT, or an isocaloric HFMCT diet displayed a similar body weight gain over 8 weeks of treatment. Only HFLCT increased myocellular TAG (42.3 ± 4.9, 71.9 ± 6.7, and 48.5 ± 6.5 µmol/g for LF, HFLCT, and HFMCT, respectively, P <0.05) and long-chain acylcarnitine content (P <0.05). Neither HF diet increased myocellular diacylglycerol (DAG) content. Intraperitoneal (IP) glucose tolerance tests (1.5 g/kg) revealed a significantly decreased glucose tolerance in the HFMCT compared to the HFLCT-fed rats (802 ± 40, 772 ± 18, and 886 ± 18 area under the curve for LF, HFLCT, and HFMCT, respectively, P <0.05). Finally, no differences in myocellular insulin signaling after bolus insulin injection (10 U/kg) were observed between LF, HFLCT, or HFMCT-fed rats. These results show that accumulation of TAGs and acylcarnitines in skeletal muscle in the absence of body weight gain do not impede myocellular insulin signaling or whole-body glucose intolerance.
AB - Accumulation of triacylglycerols (TAGs) and acylcarnitines in skeletal muscle upon high-fat (HF) feeding is the resultant of fatty acid uptake and oxidation and is associated with insulin resistance. As medium-chain fatty acids (MCFAs) are preferentially ß-oxidized over long-chain fatty acids, we examined the effects of medium-chain TAGs (MCTs) and long-chain TAGs (LCTs) on muscle lipid storage and whole-body glucose tolerance. Rats fed a low-fat (LF), HFLCT, or an isocaloric HFMCT diet displayed a similar body weight gain over 8 weeks of treatment. Only HFLCT increased myocellular TAG (42.3 ± 4.9, 71.9 ± 6.7, and 48.5 ± 6.5 µmol/g for LF, HFLCT, and HFMCT, respectively, P <0.05) and long-chain acylcarnitine content (P <0.05). Neither HF diet increased myocellular diacylglycerol (DAG) content. Intraperitoneal (IP) glucose tolerance tests (1.5 g/kg) revealed a significantly decreased glucose tolerance in the HFMCT compared to the HFLCT-fed rats (802 ± 40, 772 ± 18, and 886 ± 18 area under the curve for LF, HFLCT, and HFMCT, respectively, P <0.05). Finally, no differences in myocellular insulin signaling after bolus insulin injection (10 U/kg) were observed between LF, HFLCT, or HFMCT-fed rats. These results show that accumulation of TAGs and acylcarnitines in skeletal muscle in the absence of body weight gain do not impede myocellular insulin signaling or whole-body glucose intolerance.
KW - muscle insulin-resistance
KW - skeletal-muscle
KW - differential oxidation
KW - energy-expenditure
KW - acids
KW - triglycerides
KW - metabolism
KW - transport
KW - carnitine
KW - mechanism
U2 - 10.1038/oby.2010.152
DO - 10.1038/oby.2010.152
M3 - Article
SN - 1930-7381
VL - 19
SP - 792
EP - 799
JO - Obesity
JF - Obesity
IS - 4
ER -
