INFLUENCE OF AGE AND SEX ON VITAMIN-B6 VITAMER DISTRIBUTION AND ON VITAMIN-B6 METABOLIZING ENZYMES IN WISTAR RATS
INFLUENCE OF AGE AND SEX ON VITAMIN-B6 VITAMER DISTRIBUTION AND ON VITAMIN-B6 METABOLIZING ENZYMES IN WISTAR RATS
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DOI：
10.1093/jn/121.3.318
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发表时间：
1991-03-01
影响因子：
4.2
通讯作者：
VANDENBERG, H
中科院分区：
文献类型：
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作者：
BODE, W;MOCKING, JAJ;VANDENBERG, H
从断奶至31月龄，在喂食纯化饲料（含250 g酪蛋白和6 mg盐酸吡哆醇/kg）的老龄雄性和雌性Wistar大鼠中评价维生素B-6维生素分布和维生素B-6代谢酶活性。血浆5 '-磷酸吡哆醛（PLP）浓度随着年龄的增长而降低，在生命的第一年下降幅度最大。观察到维生素B-6在不同组织中分布的年龄相关变化：心脏和大脑中的B-6维生素含量增加，而腓肠肌、肾脏和肝脏中的PLP含量减少。肌肉PLP含量的减少与肌糖原磷酸化酶活性的降低一致。尿中4-吡哆酸（4-PA）排泄量随年龄增长而增加，尤其是在雌性大鼠中，与肝脏吡哆醛氧化酶和吡哆醛脱氢酶活性的增加平行。维生素B-6分布中的代谢相关变化可能与维生素B-6代谢酶活性变化无因果关系;它们被视为蛋白质代谢变化的结果。老年大鼠尿4-PA排泄量较高可能反映了维生素B-6需求量较低;然而，腓肠肌PLP含量较低可能表明维生素B-6体内储存量与年龄相关性降低。
Vitamin B-6 vitamer distribution and activities of vitamin B-6 metabolizing enzymes were evaluated in aging male and female Wistar rats fed a purified diet (containing 250 g of casein and 6 mg of pyridoxine hydrochloride per kg) from weaning until 31 mo of age. Plasma pyridoxal 5'-phosphate (PLP) concentration became lower with increasing age, with the largest decrease in the 1st yr of life. An age-related change in vitamin B-6 distribution between the various tissues examined was observed: B-6 vitamer content increased in heart and brain, whereas PLP content decreased in gastrocnemius muscle, kidney and liver. The decrease in muscle PLP content occurred in concert with a decrease in muscle glycogen phosphorylase activity. Urinary 4-pyridoxic acid (4-PA) excretion increased with age, especially in female rats, in parallel with an increase in liver pyridoxal oxidase and pyridoxal dehydrogenase activities. Age-related changes in vitamin B-6 distribution were probably not causally related to changes in activity of vitamin B-6 metabolizing enzymes; they were regarded as consequences of changes in protein metabolism. The higher urinary 4-PA excretion in older rats may reflect a lower vitamin B-6 requirement; however, the lower PLP content of gastrocnemius muscle may indicate an age-related decrease in vitamin B-6 body stores.