表題番号：2003A-595
日付：2006/04/01
研究課題エタノールの嗜好性と非嗜好性マウスにおける肝臓内エタノール代謝関連酵素活性の比較
| 研究者所属（当時） | 資格 | 氏名 | |
|---|---|---|---|
| （代表者） | 人間科学学術院 | 教授 | 今泉 和彦 |
- 研究成果概要
- Purpose : Alcohol dehydrogenase (ADH；alcohol:NAD+ oxidoreductase) is the principal enzyme responsible for ethanol oxidation. Although the exact physiological role of ADH is less understood, it catalyzes the reduction or oxidation of a variety of steroidal and non-steroidal substrates in addition to ethanol. It is well established that ethanol preferences are important factors for evaluating the ethanol drinking capacity. However, the relationship between ethanol preference and ethanol drinking capacity is unknown. The elucidation of this problem is essential for better understanding of ethanol drinking-induced physiological actions. On the other hand, ethanol drinking capacities are known to be obviously higher in C57BL/6J (=high ethanol preference) mice than in DBA/2J (=low ethanol preference) mice. Little information, however, is available concerning the relation between ADH activity and the level of ethanol preference in mice. Therefore, the present study was examined to clarify the relation between C57BL/6J and mice and DBA/2J mice in the ADH activities and the preference for ethanol. The relation between male and female in ADH activities in both strain mice was also studied.
Methods and Materials : 7 weeks old male and female C57BL/6J and DBA/2J mice were used. All liver homogenates were prepared in ice-cold 0.1 % Triton X-100 in 0.9 % NaCl solution. Liver cytosolic fractions were prepared by ultracentrifuge (105,000 g for 60 min), and used for the determination of ADH activity. The ADH activities were assayed at 38℃ and pH 9.0 and expressed as the amount of enzyme that produces 1 nmol of NADH per min per mg protein.
Results and Conclusion : The liver weight per body weight showed no significant difference in parallel between two species (C57BL/6J and DBA/2J) in both sexes or both sexes in two species. However, the specific ADH activities and total ADH activities of both strain mice were about 1.33 times significantly higher in female than in male. These results agreed with our recent findings in rats (J Nutr Sci Vitaminol, 46 : 49-52, 2000). The specific ADH activities and total ADH activities of male and female C57BL/6J mice were about 1.54–1.56 times significantly higher than those of male and female DBA/2J mice, suggesting that the liver ADH activities depend upon the level of the preference for ethanol and are influenced by sex-hormones.