Bárdos L
Department of Animal Physiology and Health, University of Agricultural Sci., Gödöllö, Hungary.
Int J Vitam Nutr Res. 1996;66(1):31-5.
Absorption of retinyl acetate (RA) was studied in hens. Animals (n = 10-10) received 12.5-,25-,50-,100-,150-,200-,250- and 300 x 10(3) IU of RA in capsules (p.os). Before treatment (0) and 2nd, 4th, 6th and 8th hours later, as well as on the following day blood samples were taken for retinoid analysis. Vitamin A peaks were detected in the blood in the 4th hour. The alterations in the plasma vitamin A levels were caused basically by the elevations of the retinyl ester (RYL) fraction. The proportion of RYL was 7-27% of the total plasma vitamin A value in all groups at the time of RA administration (0 h). This RYL ratio was elevated parallel to RA doses, and in case of higher doses reached 80-90% (4th h). It has been found that the efficiency of RA absorption, in hens, is in inverse ratio to the dose that is used. The calculated relative absorption coefficients of efficiency have a close negative correlation (r = -0.89; p < 0.01) to the doses. Relationship between the maximum plasma retinoid concentrations and the dose/metabolic body mass can be fitted to the saturation function. It seems reasonable to conclude that in hens the absorption of retinol is an enzyme dependent and/or carrier mediated process even in cases of pharmacological doses.
在母鸡中研究了醋酸视黄酯（RA）的吸收情况。动物（每组n = 10）口服胶囊形式的12.5-、25-、50-、100-、150-、200-、250-和300×10³IU的RA。在治疗前（0小时）以及之后的第2、4、6和8小时，还有次日采集血样进行类视黄醇分析。在第4小时血液中检测到维生素A峰值。血浆维生素A水平的变化主要是由视黄酯（RYL）部分的升高引起的。在给予RA时（0小时），所有组中RYL的比例占血浆总维生素A值的7-27%。该RYL比例随RA剂量平行升高，在高剂量情况下达到80-90%（第4小时）。已发现母鸡中RA的吸收效率与所用剂量成反比。计算出的相对吸收效率系数与剂量呈密切负相关（r = -0.89；p < 0.01）。血浆类视黄醇最大浓度与剂量/代谢体重之间的关系可以拟合为饱和函数。可以合理地得出结论，即使在药理剂量情况下，母鸡中视黄醇的吸收也是一个酶依赖性和/或载体介导的过程。
