Brass E P, Hoppel C L
J Biol Chem. 1978 Aug 10;253(15):5274-6.
1-Carnitine was administered to fed rats and the changes in plasma beta-hydroxybutrate concentration and liver acid-insoluble acylcarnitine content were assessed. One hour following injection of carnitine in doses greater than 1 mumol/100 g of body weight there was a dose-dependent increase in liver acid-insoluble acylcarnitine content to levels comparable to those seen in fasting. These increased levels were maintained for a least 2 h following injection. During the period following carnitine administration there was no increase in ketogenesis as evidenced by plasma beta-hydroxybutyrate concentrations. Since acid-insoluble acylcarnitines represent the product of carnitine palmitoyltransferase A, the results are interpreted as contradictory to the theory that this enzyme is rate-limiting and regulatory for ketogenesis.
给喂食后的大鼠注射肉碱，并评估血浆β-羟基丁酸浓度和肝脏酸不溶性酰基肉碱含量的变化。注射剂量大于1μmol/100g体重的肉碱1小时后，肝脏酸不溶性酰基肉碱含量呈剂量依赖性增加，达到与禁食时相当的水平。注射后这些升高的水平至少维持2小时。在给予肉碱后的这段时间内，血浆β-羟基丁酸浓度表明生酮作用没有增加。由于酸不溶性酰基肉碱代表肉碱棕榈酰转移酶A的产物，这些结果被解释为与该酶对生酮作用具有限速和调节作用的理论相矛盾。
