title: The utilization by rabbit aorta of carbohydrates, fatty acids, ketone bodies, and amino acids as substrates for energy production.
abstract: The ability of rabbit aorta to oxidize various substrates was studied to determine which of these compounds may be energy substrates for vascular smooth muscle (VSM). Glucose, ketone bodies, medium-chain length fatty acids, branched-chain amino acids, and glutamine all are oxidized at comparable rates on a molar basis. Some other amino acids, long chain fatty acids, pyruvate and glycerol also are oxidized, but at lower rates. The oxidation of 6 amino acids could not be detected. VSM was found to release ketone bodies when incubated in leucine beta-hydroxybutyrate or octanoate. This suggests that the acetoacetyl CoA and/or acetoacetate derived from these substrates is not completely oxidized. The oxidation rate of several substrates when measured individually is inhibited by 50-80% by the presence of a combination of other substrates in the medium. Under these conditions, glucose is a minor substrate for oxidative metabolism accounting for only 5% of O2 consumption. The oxidation rate of all the exogenous substrates together is calculated to account for less than half of the oxygen consumption; this finding indicates that an endogenous substrate must also be utilized.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D004734:Energy Metabolism; D005227:Fatty Acids / Q000378:metabolism*; D007657:Ketone Bodies / Q000378:metabolism; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D010101:Oxygen Consumption; D011817:Rabbits
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D007657:Ketone Bodies; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate