retinol-palmitate and Dermatitis--Contact

Overuse of vitamin A as a dietary supplement is a concern in industrialized countries. High-level dietary vitamin A is thought to shift immunity to a T helper 2 (Th2)-dominant one, resulting in the promotion of allergies. We have been studying a fluorescein isothiocyanate (FITC)-induced contact hypersensitivity (CHS) mouse model that involves Th2-type immunity. We fed a diet with a high retinyl palmitate content (250 international units (IU)/g diet) or a control diet (4 IU/g diet) to BALB/c mice for three weeks. No augmentation of FITC-induced CHS was found in mice fed the diet with a high vitamin A content, although accumulation of the vitamin was confirmed in the livers of these animals. The results indicated that relatively short-term feeding of the high-level vitamin A diet did not influence the Th2-driven response at a stage with significant retinol accumulation in the liver. The results were in contrast to the high-dose pyridoxine diets that produced a reduced response in FITC-induced CHS.

Topics: Animals; Dermatitis, Contact; Diet; Dietary Supplements; Disease Models, Animal; Diterpenes; Fluorescein; Fluorescein-5-isothiocyanate; Isothiocyanates; Liver; Mice, Inbred BALB C; Pyridoxine; Retinyl Esters; Severity of Illness Index; Th1-Th2 Balance; Th2 Cells; Vitamin A

Topics: Dermatitis, Contact; Diterpenes; Drug Eruptions; Female; Humans; Middle Aged; Retinyl Esters; Vitamin A