Isa Yasuka, Tsuge Haruhito, Hayakawa Takashi
The United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
J Nutr Sci Vitaminol (Tokyo). 2006 Oct;52(5):302-6. doi: 10.3177/jnsv.52.302.
The objective of this study was to clarify the relationship between the accumulation of S-adenosylhomocysteine (SAH) and the change in the SAH hydrolase activity in vitamin B6 (B6). Male Wistar rats were fed a control diet (control and pair-fed groups) or B6-free diet (B6-deficient group) for 5 wk. Although the SAH-synthetic activity of SAH hydrolase significantly increased in the B6-deficient group, SAH-hydrolytic activity of SAH hydrolase showed no significant difference in the liver among the three groups. On the other hand, SAH hydrolase mRNA in the liver did not show any significant change. Thus, the accumulation of SAH would be due to the increased SAH-synthetic activity of SAH hydrolase. The disturbed methionine metabolism by B6-deficiency, such as a significant increase of plasma homocysteine, might induce the activation of SAH hydrolase in the direction of SAH synthesis.
本研究的目的是阐明维生素B6（B6）缺乏时S-腺苷同型半胱氨酸（SAH）的蓄积与SAH水解酶活性变化之间的关系。将雄性Wistar大鼠分为对照组（正常对照组和配对喂养组）或无B6饮食组（B6缺乏组），喂养5周。尽管B6缺乏组中SAH水解酶的SAH合成活性显著增加，但三组大鼠肝脏中SAH水解酶的SAH水解活性无显著差异。另一方面，肝脏中SAH水解酶mRNA未显示任何显著变化。因此，SAH的蓄积可能是由于SAH水解酶的SAH合成活性增加所致。B6缺乏引起的蛋氨酸代谢紊乱，如血浆同型半胱氨酸显著升高，可能会诱导SAH水解酶向SAH合成方向激活。
