Comparative distribution of beta-carotene and lycopene after intraperitoneal administration in mice.

To determine the kinetics of accumulation of beta-carotene and lycopene, and their main storage sites, they were separately administered in OFI mice at a single dose of 10 mg/kg body weight or in combination. Animals were sacrificed at given time intervals after intraperitoneal administration and carotenoids were dosed in serum, liver, spleen, kidneys and lungs. A single injection of beta-carotene led to a serum peak at t = 2 h and high levels were detected in the liver after 0.75 hours and in the spleen after 5 hours, with peak values of 10.46 +/- 0.62 and 134 +/- 6 micrograms/g tissue respectively. In contrast, lungs and kidneys did not appear as main accumulation sites. After administration of the carotenoid association, beta-carotene distribution in the four organs was strongly inhibited by lycopene. Concerning lycopene distribution, the concentration values were lower than beta-carotene, the spleen and liver remaining the main storage sites. After administration of a combined dose carotene/lycopene, the percentage of lycopene distribution inhibition was lower compared to the beta-carotene distribution inhibition induced by lycopene. This unusual and non-physiological way of administration for micronutrients leads to high levels of beta-carotene and lycopene in the liver and spleen, and seems of interest in the experimental study and understanding of the biomolecular mechanisms of their activities when administered alone or together.