Mongolian gerbils (Meriones unguiculatus) absorb beta-carotene intact from a test meal

Because a yellow color has been observed in the fat pads of Mongolian gerbils fed a nonpurified diet, we designed the current study to determine whether adult male gerbils would absorb beta-carotene intact from a test meal. Thirty-five gerbils (80-90 g) were adapted to the laboratory and fed a standard purified diet free of beta-carotene for 16-19 d. Gerbils were then fed a test meal consisting of 279 nmol of beta-carotene as 10% water-soluble beadlets suspended in 0.5 mL of Ensure. Gerbils (n = 5) were killed at 0, 2, 4, 6, 12, 24 or 72 h after the test meal, blood was obtained by cardiac puncture, and tissues were taken for beta-carotene analysis. No beta-carotene was detected in serum at 0 or 72 h, whereas beta-carotene was present at all other sampling times. Serum beta-carotene peaked at 4 h, at a level of 88 nmol/L. beta-Carotene was detected in the liver of all groups; however, the concentration increased from -34 pmol/g to a maximum concentration of 926 pmol/g at 24 h after the test meal. Other tissues also contained beta-carotene. The results demonstrate that Mongolian gerbils, like ferrets and preruminant calves, absorb beta-carotene intact when beta-carotene is provided at a physiological level in a test meal. This species may be particularly useful for evaluation of the role of antioxidants, such as beta-carotene, in LDL oxidation.