Hepatic β-carotene stores decrease markedly prior to vitamin A deficiency in the Mongolian gerbil

The objective of this work was to monitor the loss of hepatic β-carotene (βC) during vitamin A (VA) depletion of three week old male Mongolian gerbils. For the first 7 days, groups (n=15) C, E, and G were fed a +VA-βC diet (6 μg VA/g diet), while groups D, F, and H were fed a +VA+βC diet (2 μg VA, 37.8 Hg βC/g diet). The gerbils were then given a diet free of VA and βC for the remainder of the study. At various intervals groups of gerbils were killed, and the liver and other tissues taken for VA and βC analysis using HPLC. Groups C/D, E/F, and G/H were killed 0, 28, and 84 days, respectively, after the initial 7 day feeding period. As expected, total liver VA stores decreased at each kill period (173, 157, 43 μg for groups C, E, and G, and 156, 128, 36 μg for groups D, F, H, respectively). There were no statistically significant differences in VA stores found between groups C/D, E/F, or G/H in the liver, kidney, adrenal or serum, nor were there significant decreases in VA in extrahepatic tissues during the study. Group D had an average total βC content of 6.9 μg in the liver. Within one month this value was 1.1 μg(F) and at the end of 3 months, the average βC content was 0.2 μg(H). βC content in the adrenals followed this same trend, while βC content in the remaining tissues was negligible in all groups. Overall, the data suggests that when the gerbil is fed a VA deficient diet, hepatic βC stores are lost fairly rapidly and are not conserved for later VA deficiency.