Tanumihardjo S A, Olson J A
Department of Biochemistry and Biophysics, Iowa State University, Ames 50011.
Eur J Clin Nutr. 1991 Aug;45(8):407-11.
The modified relative dose response (MRDR) assay is a minimally invasive method of detecting marginal vitamin A status. In the present study, the MRDR assay was performed four times in six well-nourished adults and in one male five-year-old child over a seven-month period. In all instances, assay ratios of dehydroretinol (DR) to retinol (R) were less than 0.03, the tentative cutoff value of 'normal' for the MRDR assay in humans. The mean ratio for all time points for all individuals was 0.015 +/- 0.005, with a mean coefficient of variation of 27 +/- 13%. In a related experiment, both MRDR and conjunctival impression cytology (CIC) tests were conducted on nine adults and the same male child. All DR/R ratios were less than or equal to 0.021, and all CIC specimens were normal. Thus, the DR/R ratio in well-nourished individuals, although showing some variation, does not oscillate between abnormal and normal responses. Furthermore, the DR/R ratios and CIC patterns were fully concordant.
改良相对剂量反应（MRDR）测定法是一种检测边缘性维生素A状态的微创方法。在本研究中，在7个月的时间里，对6名营养良好的成年人和1名5岁男性儿童进行了4次MRDR测定。在所有情况下，脱氢视黄醇（DR）与视黄醇（R）的测定比值均小于0.03，这是人类MRDR测定“正常”的暂定临界值。所有个体所有时间点的平均比值为0.015±0.005，平均变异系数为27±13%。在一项相关实验中，对9名成年人和同一名男性儿童进行了MRDR和结膜印迹细胞学（CIC）检测。所有DR/R比值均小于或等于0.021，所有CIC标本均正常。因此，营养良好个体的DR/R比值虽然存在一些变化，但不会在异常和正常反应之间波动。此外，DR/R比值和CIC模式完全一致。
