大鼠体内[75Se]硒代胱氨酸和[75Se]硒代蛋氨酸的代谢研究。

Metabolic studies of [75Se]selenocystine and [75Se]selenomethionine in the rat.

Thomson C D, Robinson B A, Stewart R D, Robinson M F

Br J Nutr. 1975 Nov;34(3):501-9. doi: 10.1017/s0007114575000542.

Abstract

The long-term fate in rats of an oral dose of [75Se]selenocystine was compared with that of an oral dose of [75Se]selenomethionine. 2. Urinary and faecal radioactivities were measured during the 1st week and whole-body radioactivity was determined for 10 weeks. Rats were killed at weekly intervals for 4 weeks and at weeks 6 and 10 for analysis of tissue distribution of 75Se. 3. Intestinal absorption of [75Se]selenocystine was 81% of the administered dose; that of [75Se]selenomethionine was 86%. Urinary excretion of absorbed [75Se]selenocystine was 13-9% and that of [75Se]selenomethionine was 5-8% in the 1st week. 4. Whole-body retention of 75Se was greater for [75Se]selenomethionine than for [75Se]selenocystine but after the 1st week it decreased at a similar rate in both groups. Tissue distribution of retained 75Se was also similar in both groups. 5. The initial utilization of [75Se]selenocystine was different from that of [75Se]selenomethionine. However, after the 1st week 75Se from both sources appeared to be metabolized similarly, suggesting that dietary Se of both forms is ultimately incorporated into the same metabolic pool. 6. When these findings were compared with those of earlier studies with [75Se]selenite and 75Se incorporated in vivo into rabbit kidney (RK-64Se) (Thomson, Stewart & Robinson, 1975) the metabolism of [75Se]selenocystine resembled that of [75Se]selenite and RK-75Se, rather than that of [75Se]selenomethionine.

摘要

将口服剂量的[75Se]硒代胱氨酸在大鼠体内的长期归宿与口服剂量的[75Se]硒代蛋氨酸的长期归宿进行了比较。2. 在第1周测量尿和粪便放射性，并在10周内测定全身放射性。大鼠在4周内每周处死一次，在第6周和第10周处死以分析75Se的组织分布。3. [75Se]硒代胱氨酸的肠道吸收率为给药剂量的81%；[75Se]硒代蛋氨酸的肠道吸收率为86%。在第1周，吸收的[75Se]硒代胱氨酸的尿排泄率为13 - 9%，[75Se]硒代蛋氨酸的尿排泄率为5 - 8%。4. [75Se]硒代蛋氨酸的75Se全身保留率高于[75Se]硒代胱氨酸，但在第1周后，两组的下降速率相似。保留的75Se的组织分布在两组中也相似。5. [75Se]硒代胱氨酸的初始利用与[75Se]硒代蛋氨酸不同。然而，在第1周后，来自两种来源的75Se的代谢似乎相似，这表明两种形式的膳食硒最终都被纳入相同的代谢池。6. 当将这些发现与早期用[75Se]亚硒酸盐和体内掺入兔肾的75Se（RK - 64Se）（汤姆森、斯图尔特和罗宾逊，1975年）的研究结果进行比较时，[75Se]硒代胱氨酸的代谢类似于[75Se]亚硒酸盐和RK - 75Se的代谢，而不是[75Se]硒代蛋氨酸的代谢。