Interactive effects of an oral dose of equal quantities of beta-carote
ne and either canthaxanthin or lycopene on serum and tissue beta-carot
ene accumulations were investigated in domestic ferrets. Like humans,
ferrets absorb a substantial portion of ingested beta-carotene intact
and accumulate it in tissues. After the ferrets ingested a low caroten
oid purified diet for 13 d, they were randomly assigned to one of two
groups of six animals. One group was dosed with beta-carotene (10 mg/k
g body weight) and the other with beta-carotene and either canthaxanth
in (Experiment 1) or lycopene (Experiment 2) (10 mg/kg body weight for
each). In Experiment 1, ferrets that received a combined dose of beta
-carotene and canthaxanthin had serum beta-carotene concentrations tha
t were significantly lower at 8, 12 and 24 h post-dosing (P < 0.05), c
ompared with those that received an individual dose of beta-carotene;
liver, adrenal and kidney beta-carotene concentrations were also signi
ficantly reduced. In Experiment 2, ferrets that received a combined do
se of lycopene and beta-carotene had lower serum and tissue beta-carot
ene concentrations than in those that received beta-carotene alone; th
e differences were not statistically significant with the exception of
serum beta-carotene concentrations at 24 h post-dosing. The results s
uggest that, at the doses given, a concurrent oral canthaxanthin dose
has a specific antagonistic effect on the bioavailability of a beta-ca
rotene dose in ferrets.