| Autor: |
Geelen, Suzanne N. J., Bl??zquez, Cristina, Geelen, Math J. H., Sloet van Oldruitenborgh-Oosterbaan, Marianne M., Beynen, Anton C. |
| Zdroj: |
British Journal of Nutrition; Jul2001, Vol. 86 Issue 1, p31-36, 6p |
| Abstrakt: |
The metabolic effects of feeding soyabean oil instead of an isoenergetic amount of maize starch plus glucose were studied in ponies. Twelve adult Shetland ponies were given a control diet (15 g fat/kg DM) or a high-fat diet (118 g fat/kg DM) according to a parallel design. The diets were fed for 45 d. Plasma triacylglycerol (TAG) concentrations decreased by 55 % following fat supplementation. Fat feeding also reduced glycogen concentrations significantly by up to 65 % in masseter, gluteus and semitendinosus muscles (P<0??05, P<0??01 and P<0??01 respectively). The high-fat diet significantly increased the TAG content of semitendinosus muscle by 80 % (P<0??05). Hepatic acetyl-CoA carboxylase and fatty acid synthase activities were 53 % (P<0??01) and 56 % (P<0??01) lower respectively in the high-fat group, but diacylglycerol acyltransferase activity was unaffected. Although carnitine palmitoyltransferase-I (CPT-I) activity in liver mitochondria was not influenced, fat supplementation did render CPT-I less sensitive to inhibition by malonyl-CoA. There was no significant effect of diet on the activity of phosphofructokinase in the different muscles. The activity of citrate synthase was raised significantly (by 25 %; P<0??05) in the masseter muscle of fat-fed ponies, as was CPT-I activity (by 46 %; P<0??01). We conclude that fat feeding enhances both the transport of fatty acids through the mitochondrial inner membrane and the oxidative capacity of highly-aerobic muscles. The higher oxidative ability together with the depressed rate of de novo fatty acid synthesis in liver may contribute to the dietary fat-induced decrease in plasma TAG concentrations in equines. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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