Histochemical and histopathological changes in the skin of rats after manganese application

Abstract

Histochemical and histopathological changes in the skin of rats, after the daily application of manganese chloride solution for a period of 90 days, are reported. These alterations consist of hyperkeratinization and marked proliferation of hair follicles. The application of manganese chloride solution produced marked inhibition in the activities of succinic dehydrogenase, glucose-6-phosphate dehydrogenase and cytochrome oxidase, however no effect was noticed in the activities of acid and alkaline phosphatases, melanin deposition and the contents of nucleic acids in the skin of rats. The intensity of staining reaction for sulfhydryl groups appeared markedly increased due to the proliferation of the hair follicles in the painted skin. The absence of any effect on the cutaneous melanin appears of significance since manganese has been found to reduce neuromelanin in rhesus monkeys. The implications of these findings are discussed.