A new model for producing vitamin A deficiency in rats.

To produce a rapid depletion of vitamin A, an experimental approach based on partial hepatectomy (60%) to remove stores and feeding a vitamin A deficient diet during recovery was tested in weanling and adult wistar rats. Plasma and liver vitamin A levels were determined at appropriate time points along with food intakes and body weights. Adult rats fed a deficient diet for a period of one month during regeneration, exhibited significantly lower values (mean +/- SE) of liver vitamin A (176 +/- 19 micrograms/g) compared to controls (256 +/- 41 micrograms/g) receiving vitamin A supplements. However, these levels are not in the deficient range and the plasma vitamin A levels were not altered. Therefore, adult animals were not considered a suitable model for such experiments. In similar experiments with weanling rats, sham-operated controls kept on a vitamin A-free diet showed a liver vitamin A concentration of 16 +/- 1.2 micrograms/g after six weeks. Hepatectomized animals kept on a similar diet showed 5.2 +/- 1.1 micrograms/g liver in contrast to those fed on a vitamin A supplemented diet (328 +/- 27 micrograms/g). Also, the plasma vitamin A of hepatectomized animals on a vitamin A-deficient diet was very low (4.3 +/- 1.5 micrograms/dl) as compared to that in either supplemented or sham-operated controls. Thus rapid deficiency of nutrients like vitamin A could be produced using a hepatectomy and regeneration model in weanling rats, which otherwise may take much longer time.