Essential fatty acid deficient hairless mouse: the effects of topical agents on the epidermis

Abstract

Essential fatty acid deficient (EFA deficient) hairless mice were used to test the ability of topical agents to reduce the high epidermal DNA synthesis and acanthosis present in EFA deficiency. An established therapeutic agent (betamethasone 17-valerate) known to be effective in psoriasis significantly reduced the epidermal DNA synthesis, mitotic count and epidermal cell thickness. Linoleic acid reduced DNA synthesis and returned epidermal histology toward that of normal skin. Prostaglandin[PG]E2 analogue (15(S)-15-methyl PGE2 methyl ester) reduced epidermal DNA synthesis in treated and distant skin sites. PGE2 was less effective than the analogue but slightly reduced epidermal DNA synthesis and thickness. PGF2.alpha. had no obvious effect on the epidermis. Chlorambucil reduced epidermal DNA synthesis and thickness. Vitamin A acid increased DNA synthesis and epidermal cell thickness but reduced the hyperkeratosis of EFA deficiency. A rapid epidermal cell transit was found in EFA deficient mice .apprx. 3 times faster than in normal mouse epidermis.