期刊名称:Journal of Nutritional Science and Vitaminology
印刷版ISSN:0301-4800
电子版ISSN:1881-7742
出版年度:1978
卷号:24
期号:1
页码:9-23
DOI:10.3177/jnsv.24.9
出版社:Center for Academic Publications Japan
摘要:Studies were conducted to investigate the in vivo and in vitro effects of retinol and retinoic acid on the synthesis of mannolipids and mannopeptides in rat liver. The incorporation of 14C-mannose into glycolipids and glycoproteins showed a decrease in vitamin A-depleted rats as compared with vitamin A-fed rats. By means of DEAE-cellulose, silicic acid and thin-layer chromatography, the mannose-containing lipids were separated into mannosyl retinyl phosphate (MRP, Rf 0.2) and dolichyl mannosyl phosphate (DMP, Rf 0.4), respectively. A rapid increase in the synthesis of labelled MRP was observed, exhibiting a peak between 25 and 60 min after intraperitoneal administration of retinol to vitamin A-depleted rats. Similarly, administration of retinoic acid brought about elevation of 14C mannolipid ( Rf 0.2) synthesis with a peak at 60 min after injection. On the other hand, the incorporation of 14C-mannose into DMP ( Rf 0.4) remained unchanged by such treatment. In vitro addition of retinyl phosphate, but not retinoyl phosphate, markedly stimulated the synthesis of 14C-mannolipid ( Rf 0.2), using crude membrane of rat liver and GDP 14C-mannose as the donor. These findings strongly suggest that not only retinol but also retinoic acid plays an important biological role in man nosyl transfer reaction in rat liver. However, the molecular participation of a metabolity of retinoic acid in the formation of a mannolipid and the structure of such a metabokite remain to be established.