Odessey R, Chace K V
Am J Physiol. 1982 Jul;243(1):H128-32. doi: 10.1152/ajpheart.1982.243.1.H128.
The utilization of endogenous stores by rabbit aorta in vitro was measured. In substrate-free medium glycogen disappearance may account for less than 20% of the tissue O2 consumption during incubations of less than 2-3 h. At longer times (or in the presence of glucose) glycogen catabolism is negligible. Calculations from the rate of proteolysis suggest that oxidation of endogenously generated amino acids accounts for less than 7-10% of the oxygen consumption. Furthermore, the presence of amino-oxyacetate, a transaminase inhibitor, did not alter the ATP-ADP ratio. By contrast, measurements of the disappearance of tissue triglyceride indicate that endogenous lipid could meet the fuel requirements of the aorta. Direct measurement of intracellular fatty acid oxidation was obtained by measuring acyl carnitine specific activity and 14CO2 production from [1-14C]palmitate. Fatty acid oxidation could account for at least 90% of the total O2 consumption, and 83% of the fatty acids consumed were derived from endogenous tissue stores. Octanoate was found to inhibit both exogenous and endogenous fatty acid oxidation. These findings may indicate that shorter-chain fatty acids may be preferentially utilized by the aorta.
测定了兔主动脉在体外对内源储备的利用情况。在无底物培养基中，糖原消失在孵育少于2 - 3小时的过程中可能占组织耗氧量的不到20%。在更长时间（或存在葡萄糖的情况下），糖原分解可忽略不计。根据蛋白水解速率计算表明，内源性生成氨基酸的氧化占耗氧量的不到7 - 10%。此外，转氨酶抑制剂氨基氧乙酸的存在并未改变ATP - ADP比值。相比之下，组织甘油三酯消失的测量结果表明，内源性脂质可以满足主动脉的燃料需求。通过测量酰基肉碱比活性和[1 - 14C]棕榈酸产生的14CO2，直接测定了细胞内脂肪酸氧化。脂肪酸氧化至少占总耗氧量的90%，消耗的脂肪酸中有83%来自内源性组织储备。发现辛酸可抑制外源性和内源性脂肪酸氧化。这些发现可能表明主动脉可能优先利用较短链脂肪酸。
