出版社：American Society for Biochemistry and Molecular Biology
摘要：Vitamin A (VA) is stored in tissues predominantly as retinylesters (REs), which provide substrate for the production ofbioactive retinoids. Retinoic acid (RA), a principal metabolite,has been shown to induce postnatal lung development. To betterunderstand lung RE storage, we compared VA (given as retinylpalmitate), RA, and a nutrient-metabolite combination, VARA,given orally on postnatal days 5–7, for their abilityto increase lung RE in neonatal rats. VARA increased lung REsignificantly [14, 2.4, 2.1, and <1 nmol/g for VARA, VA,RA, and control (C), respectively; P < 0.001]; the increaseby VARA was more than additive compared with the effects ofVA and RA alone. Lung histology and morphometry were unchanged.In a 6 h metabolic study, providing [3H]retinol with VARA, comparedwith VA or C, increased the uptake of newly absorbed 3H by 3-fold,indicating that VARA stimulated the uptake of [3H]retinol andits retention as [3H]RE in neonatal lungs. After cessation ofVARA, lung RE remained increased for 9 d afterward, throughthe period of alveolar development. In conclusion, VARA, a 10:1nutrient-metabolite combination, increased lung RE significantlycompared with VA alone and could be a promising therapeuticoption for enhancing the delivery of VA to the lungs.Supplementary key words lung retinyl ester storage • retinol esterification • liver retinyl ester • newly absorbed retinol • neonatal vitamin A status
Abbreviations: RA, retinoic acid; RE, retinyl ester; VA, vitamin A
14, 2.4, 2.1, and <1 nmol/g for VARA, VA, RA, and control (C), respectively; P < 0.001]; the increase by VARA was more than additive compared with the effects of VA and RA alone. Lung histology and morphometry were unchanged. In a 6 h metabolic study, providing [3H]retinol with VARA, compared with VA or C, increased the uptake of newly absorbed 3H by 3-fold, indicating that VARA stimulated the uptake of [3H]retinol and its retention as [3H]RE in neonatal lungs. After cessation of VARA, lung RE remained increased for 9 d afterward, through the period of alveolar development. In conclusion, VARA, a 10:1 nutrient-metabolite combination, increased lung RE significantly compared with VA alone and could be a promising therapeutic option for enhancing the delivery of VA to the lungs.
Supplementary key words lung retinyl ester storage • retinol esterification • liver retinyl ester • newly absorbed retinol • neonatal vitamin A status
Abbreviations: RA, retinoic acid; RE, retinyl ester; VA, vitamin A
