The occurrence of
zinc-induced synthesis of
metallothionein in skin after topical application of the anti-
acne drug Zineryt lotion was investigated in hamster ears. The dinitrophenyl
hapten-sandwich immunohistochemical method involving a monoclonal anti-
metallothionein (MT) antibody (E9) was used to detect and localize
zinc-binding MT in the 'treated' and untreated hamster skin. Atomic absorption spectrophotometry and
dithizone histochemistry indicated that
zinc penetrated the skin more readily, and accumulated more efficiently within the sebaceous glands, when applied to the skin surface as the organo-
zinc complex, rather than as the inorganic
zinc salt. MT and
zinc had similar distributions in hamster skin exposed to the
metal. Thus, MT immunoreactivity was especially intense in the sebaceous glands of
Zineryt lotion-treated skin, with evidence of nuclear distribution in some cells.
Zinc delivered to the sebaceous glands, and released from the organo-complex under the prevailing aqueous conditions, certainly induced MT synthesis; the
cysteine-rich
protein may protect the pilosebaceous units during the inflammatory phase of
acne by scavenging generated oxyradical species.