The effects of vitamin A and retinoic acid supplementation to neonatal rats or dietary vitamin A supplementation to lactating mothers on vitamin A metabolism and kinetics in neonatal rats (645.20)

Abstract

The objective of the present study was to explore how vitamin A (VA) supplementation to neonatal rats or lactating mothers affects VA status and kinetics in neonatal rats. Rat pups received an oral dose of [3H]retinol admixed with oil (group 1; control group) or VARA (group 2) on postnatal day 4 (P4); pups in group 3 were given a VARA dose on P2 and P3 and received an oral dose of [3H]retinol admixed with oil on P4; the diet fed to mothers of pups in group 4 was switched from VA marginal to VA supplemented on the birth day of pups and pups received an oral dose of [3H]retinol admixed with oil on P4. Mothers in group 1, 2, and 3 were fed a VA marginal diet through the study. Pups (n=3/time) were sacrificed and tissues were collected at different time points up to P18. Compared with control group, the single VARA dose significantly increased retinol concentration in plasma, liver and lungs in the first 2‐4 days. Two‐time pre VARA dose dramatically increased liver and lung retinol concentration in the first 8 days and retinol concentration declined afterwards. The effects of both ways of VARA administration disappeared at the end of the study. The effect of maternal VA supplementation on increasing pups’ liver and lung total retinol was not as rapid as that of VARA, however, it increased with time till the end of the study. All three ways of VA supplementation decreased the fraction of [3H]retinol remaining in plasma and increased the fraction in liver and lungs. To conclude, high dose VARA to neonatal rats has a dramatic but transient effect, while dietary VA supplementation to lactating mothers has a gradually increasing and sustained effect on improving VA status in neonatal rats.Grant Funding Source: Supported by NIH