Blom H J, Boers G H, van den Elzen J P, van Roessel J J, Trijbels J M, Tangerman A
Division of Gastrointestinal and Liver Diseases, University Hospital Nijmegen, The Netherlands.
Eur J Clin Invest. 1988 Dec;18(6):633-8. doi: 10.1111/j.1365-2362.1988.tb01279.x.
Catabolism of methionine is supposed to proceed via two known pathways: transsulphuration and transamination. In 10 premenopausal women and 13 young men we measured methionine, the transsulphuration metabolite homocysteine, and the transamination metabolites 4-methylthio-2-oxo-butryate and methanethiol mixed disulphides in the fasting state as well as after oral administration of 0.1 g L-methionine kg-1 body weight. Both in the fasting state and after methionine loading the concentrations of homocysteine in serum were significantly lower in premenopausal women than in young men. Since there is evidence that even a moderate homocysteinaemia may be a risk factor in the development of vascular disease, the low homocysteine levels could be an additional factor contributing to the lower incidence of vascular disease in premenopausal women. After oral methionine these women showed significantly higher concentrations both in serum and urine of the transamination metabolites than the group of men. This higher methionine transamination in premenopausal women may contribute to keeping the homocysteine levels low and may therefore have an impact on the protection of these women against vascular disease.
转硫作用和转氨作用。我们对10名绝经前女性和13名年轻男性在空腹状态下以及口服0.1 g L-蛋氨酸/千克体重后，测量了蛋氨酸、转硫代谢产物同型半胱氨酸以及转氨代谢产物4-甲硫基-2-氧代丁酸和甲硫醇混合二硫化物。无论是在空腹状态还是蛋氨酸负荷后，绝经前女性血清中的同型半胱氨酸浓度均显著低于年轻男性。由于有证据表明，即使是中度高同型半胱氨酸血症也可能是血管疾病发生的危险因素，因此低同型半胱氨酸水平可能是绝经前女性血管疾病发病率较低的一个额外因素。口服蛋氨酸后，这些女性血清和尿液中转氨代谢产物的浓度均显著高于男性组。绝经前女性中这种较高的蛋氨酸转氨作用可能有助于维持低同型半胱氨酸水平，因此可能对保护这些女性免受血管疾病影响有作用。
