Redlich C A, Blaner W S, Van Bennekum A M, Chung J S, Clever S L, Holm C T, Cullen M R
Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Cancer Epidemiol Biomarkers Prev. 1998 Mar;7(3):211-4.
The Carotene and Retinol Efficacy Trial (CARET), a randomized, placebo-controlled lung cancer chemoprevention trial of 30 mg of beta-carotene and 25,000 IU of retinyl palmitate, was prematurely terminated when a 46% excess lung cancer mortality was found in subjects on the active arm. Before the CARET intervention ended, 21 men were recruited to participate in a 6-month biomarker study using the same intervention as CARET that determined the effect of this supplementation on lung nutrient levels. Plasma and bronchoalveolar lavage (BAL) cell nutrient levels were measured before and after the intervention. The group in the active arm (n = 10) had plasma carotene level increases of over 10-fold, with a small increase in plasma retinol levels BAL cell levels of beta-carotene in the active group also increased 10-fold, from 4.5 to 46.3 pmol/10(6) cells (P = 0.0008), with no change in BAL cell retinol levels. Surgically obtained lung tissue from three CARET subjects in the active arm showed elevated carotene lung tissue levels but no increase in lung retinol levels compared to a group of surgical controls. Combined with our previous work showing a strong correlation between BAL and lung tissue nutrient levels, these findings suggest that supplementation with beta-carotene and vitamin A results in increased lung tissue as well as BAL cell levels of beta-carotene, with little change in lung retinol.
胡萝卜素与视黄醇疗效试验（CARET）是一项针对30毫克β-胡萝卜素和25,000国际单位棕榈酸视黄酯的随机、安慰剂对照肺癌化学预防试验。当发现服用活性药物组的受试者肺癌死亡率高出46%时，该试验提前终止。在CARET干预结束前，招募了21名男性参与一项为期6个月的生物标志物研究，该研究采用与CARET相同的干预措施，以确定这种补充剂对肺部营养水平的影响。在干预前后测量血浆和支气管肺泡灌洗（BAL）细胞的营养水平。活性药物组（n = 10）的血浆胡萝卜素水平增加了10倍以上，血浆视黄醇水平略有增加。活性组BAL细胞中的β-胡萝卜素水平也增加了10倍，从4.5皮摩尔/10⁶个细胞增至46.3皮摩尔/10⁶个细胞（P = 0.0008），而BAL细胞视黄醇水平没有变化。与一组手术对照组相比，来自活性药物组的三名CARET受试者的手术获取的肺组织显示肺组织胡萝卜素水平升高，但肺视黄醇水平没有增加。结合我们之前的研究结果，即BAL与肺组织营养水平之间存在很强的相关性，这些发现表明补充β-胡萝卜素和维生素A会导致肺组织以及BAL细胞中的β-胡萝卜素水平升高，而肺视黄醇水平变化不大。
