Rabbits fed on beta-carotene have higher serum levels of all-trans retinoic acid than those receiving no beta-carotene.
The aim of the present work was to determine the effect of giving increasing doses of supplements of beta-carotene on serum retinoic acid levels in rabbits. Four groups of 7-week-old female rabbits were fed for 9 weeks on a pelleted diet containing 1.72 mg vitamin A as retinyl acetate/kg and including control gelatin beadlets devoid of beta-carotene or 1, 2 or 4 mg beta-carotene/kg body-weight per d. Serum was collected at 3, 6 and 9 weeks after the beginning of the experiment and the concentration of all-trans retinoic acid was determined by a gradient reverse-phase high-performance liquid chromatography system following a double-phase extraction. The average concentration of retinoic acid in serum of the combined control and 1 mg beta-carotene/kg groups was 3.80, 3.06 and 2.40 nM at 3, 6 and 9 weeks respectively. The concentrations of retinoic acid in serum of the combined 2 and 4 mg beta-carotene/kg groups were 4.80 nM (P less than 0.05), 3.76 nM (not significant) and 4.90 nM (P less than 0.005) at 3, 6 and 9 weeks respectively. A SAS (SAS Institute Inc., 1985) general linear model repeated-measures analysis of variance revealed that the effects of treatment (P less than 0.01), time (P less than 0.05) and treatment x time interaction (P less than 0.05) were statistically significant. It is concluded that giving beta-carotene is associated with higher concentrations of all-trans retinoic acid in the serum of rabbits than in those receiving no beta-carotene.
Folman
Y
Y
Department of Applied Biological Sciences, Massachusetts Institute of Technology, Cambridge 02139.
Russell
R M
RM
Tang
G W
GW
Wolf
D G
DG
D000818:Animals; D002338:Carotenoids / Q000008:administration & dosage / Q000494:pharmacology*; D004224:Diterpenes; D004334:Drug Administration Schedule; D005260:Female; D008099:Liver / Q000032:analysis; D011817:Rabbits; D000084562:Retinyl Esters; D014212:Tretinoin / Q000097:blood*; D014801:Vitamin A / Q000031:analogs & derivatives / Q000032:analysis; D019207:beta Carotene
D004224:Diterpenes; D000084562:Retinyl Esters; D019207:beta Carotene; D014801:Vitamin A; C014794:retinol palmitate; D002338:Carotenoids; D014212:Tretinoin