Skin Water Content as a Quantitative Index of The Vascular and Histologic Changes Produced in Rat Skin by Di-N-Butyltin and Tri-N-Butyltin

Abstract

Dibutyltin applied cutaneously at 67 nmole/cm 2 produced minor histologic changes in rat dorsal skin while the same specific dose of tributyltin produced cellular necrosis. Dibutyltin at. 335 nmole/cm 2 also produced cellular necrosis but the development of the lesion was delayed compared with that produced by tributyltin. Dibutyltin at 67 nmole/cm 2 produced only minor vascular changes in rat dorsal skin as measured by increases in vascular permeability (dye leakage), tissue water content, and degree of erythema. In contrast, the same specific dose of tributyltin and 5 times this dose of dibutyltin both produced marked increases in vascular permeability, tissue water content, and erythema, the maximum increases of which were similar for both compounds although the times for attainment of the maxima differed. When the maximum increases of the individual vascular changes were used to assess the irritancy of dibutyltin and tributyltin, the same ranking order was obtained from each parameter and this order agreed with that obtained from the histologic assessment of tissue damage. The increase in water content of skin is a representative and quantitative measure of the vascular changes produced by cutaneous application of dibutyltin and tributyltin. Skin water content measurements should, therefore, be a useful parameter in future studies of the relationship between the vascular changes produced by irritants and the corresponding cellular injury, especially if it is applicable to other irritants. It is, however, necessary to billow the time course of the response in order to determine the maximum increase in water content.