Hepatic subcellular storage of beta-carotene in rats following diet supplementation

Beta-carotene (BC) storage was measured in liver and its subcellular fracti ons (plasma membranes, mitochondria, microsomes and nuclei) of rats fed BC added to diet. The BC supplementation dose was about 350 mg/week/rat. After 15 weeks of this supplementation, rats were killed and their livers were i mmediately excised and processed to obtain total liver tissue and its subce llular fractions. Their BC contents were measured by HPLC as pmols/mg prote in. Intact BC was found to be stored in all the above subcellular fractions , thus showing that BC is probably taken up by liver cell lipid moiety. Int erestingly, the mean BC concentrations in plasma membranes and mitochondria were significantly higher than that in total liver tissue. Our data confir med that rodents are a good animal model for the study of BC metabolism and its effects on several pathologies, and cancer prevention and treatment in humans in spite of the fact that rodents are classified as white-fat anima ls because of their poor BC absorption and storage in fat and blood plasma, whereas humans are classified as yellow-fat organisms because of their opp osite behavior in BC uptake and organ distribution.