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：1996
卷号：42
期号：4
页码：267-275
DOI：10.3177/jnsv.42.267
出版社：Center for Academic Publications Japan
摘要：Our previous study revealed that no retinyl esters were detectable in chick and hen lungs, suggesting that the retinol esterification system may be absent in these tissues. This possibility encouraged us to investigate whether chick lungs exhibit the activity of a retinol esterifying enzyme, i.e., lecithin : retinol acyltransferase (LRAT). The LRAT activ ity was assayed with dilauroyl phosphatidylcholine and either complex of retinol-cellular retinol-binding protein, type two or retinol-cellular retinol binding protein in microsomal preparations of lung, duodenum and liver of 7-day-old chicks. Relatively high levels of LRAT activity were present in the duodenum and the liver of chicks as well as in the rat lung. However, the chick lung exhibited no LRAT activity. The lungs of both rat and chick showed similar and low levels of acyl-CoA : retinol acyl transferase (ARAT) activity, but only rat lung, but not chick lung, contained a detectable amount of retinyl esters. Thus, the retinyl ester storage in the lung seems to depend on the presence of LRAT activity in the lung, but it is independent of the presence of ARAT activity in the lung. The absence of LRAT activity and retinyl esters in the chick lung suggests that the retinol in the chick lung may not be provided from retinyl ester storage, and the retinol transferred directly from serum should be utilized to generate retinoic acid.
