Carotenoid and retinol concentrations in serum, adipose tissue and liver and carotenoid transport in sheep, goats and cattle

摘要

Carotenoid and retinol concentrations were determined in various tissues of sheep, goats ad ncattle, ruminants known to have widely different levels of pigmentation of their adipose tissues. nAn objective assessment of fat colour confirmed the whiteness of sheep and goat fat compared nwith that of cattle. nNo p-carotene was detected in the serum or fat of sheep and goats, but it was the npredominant carotenoid present in the serum and fat of cattle. The major pigment present nin serum and fat of sheep and goat was lutein, although its concentration was only 5-10% of nthat found in cattle. p-carotene was present in the liver of all three species with the highest nconcentration in cattle. Although lutein was the only carotenoid found in the serum and fat nof sheep and goats, it could not be detected in their livers. The concentrations of retinol in nserum and fat were similar for each species, but the liver of sheep had about three times the nretinol concentration of the liver of goats and cattle. nThe transport of carotenoids in plasma was investigated. In sheep and goats, the pigments nwere associated mainly with very low density lipoprotein (VLDL) and low density lipoprotein n(LDL), whereas in cattle, high density lipoprotein (HDL) was the major lipoprotein fraction ninvolved.