Biochemical and histopathological changes following dermal exposure to paraphenylene diamine in guinea pigs.

The guinea pigs were dermally exposed to paraphenylene diamine (PPD) at a dose level of 0.1 ml day-1 of a 1.0% (w/v) solution of PPD for 1, 3, 5 and 7 days. The absorption of PPD and its effects on lipid peroxidation, glutathione, histamine and several enzymes were assessed in skin and serum. Histopathological changes in liver, kidney and skin were examined also. The findings of the study indicated that PPD exposure resulted in significantly increased levels of lipid peroxidation and histamine contents in skin. The activity of enzymes increased significantly in skin and serum. PPD exposure also showed degenerative changes in liver and hyperkeratosis together with infiltration of cells in the dermis. Biochemical defects and histopathological changes in skin and serum correlated with the duration of exposure.