DiPadova C, Worner T M, Julkunen R J, Lieber C S
Gastroenterology. 1987 May;92(5 Pt 1):1169-73. doi: 10.1016/s0016-5085(87)91073-0.
The present investigation was undertaken to evaluate what fraction of alcohol ingested in amounts during usual "social drinking" does not enter the systemic circulation. To that effect, on consecutive days, either peroral or intravenous ethanol was administered in both fed and fasted states to 7 nonalcoholic and 18 alcoholic subjects. In nonalcoholics consuming 0.15 g/kg body wt ethanol, the magnitude of first-pass metabolism of ethanol was 3.94 +/- 0.15 mmol/L X h, calculated as the difference of the areas under the curve obtained after oral and intravenous alcohol administration. The first-pass metabolism accounted for 73% of the latter. When the administered dose was increased to 0.3 g/kg body wt ethanol, the corresponding values were 6.46 +/- 0.50 mmol/L X h and 44%. Fasting decreased this effect. When alcoholics consumed 0.15 g/kg body wt ethanol, the corresponding values were 0.92 +/- 0.65 mmol/L X h and 23%. When these alcoholics were fasted, the first-pass metabolism again decreased and it was significantly lower than in the nonalcoholics tested under the same conditions. We conclude that in humans a significant fraction of ingested alcohol undergoes first-pass metabolism but that this effect is reduced in alcoholics and by fasting. The magnitude of this process determines the bioavailability of alcohol and thus modulates its potential toxicity.
本研究旨在评估在通常“社交饮酒”量下摄入的酒精有多大比例不会进入体循环。为此，连续数天，在进食和禁食状态下，对7名非酒精依赖者和18名酒精依赖者分别经口或静脉给予乙醇。在摄入0.15 g/kg体重乙醇的非酒精依赖者中，乙醇首过代谢量为3.94±0.15 mmol/L·h，计算方法为口服和静脉给予酒精后所得曲线下面积之差。首过代谢占后者的73%。当给予剂量增加到0.3 g/kg体重乙醇时，相应的值分别为6.46±0.50 mmol/L·h和44%。禁食会降低这种效应。当酒精依赖者摄入0.15 g/kg体重乙醇时，相应的值分别为0.92±0.65 mmol/L·h和23%。当这些酒精依赖者禁食时，首过代谢再次降低，且显著低于在相同条件下测试的非酒精依赖者。我们得出结论，在人类中，摄入的酒精有很大一部分会经历首过代谢，但这种效应在酒精依赖者中以及通过禁食会降低。这个过程的程度决定了酒精的生物利用度，从而调节其潜在毒性。
