THE OCULAR EFFECTS OF REPEATED DERMAL APPLICATIONS OF DIMETHYL SULFOXIDE TO DOGS AND MONKEYS

¹ Mason Research Institute, Worcester, Massachusetts

Six dogs and 24 monkeys were divided into groups of two dogs and eight monkeys each and received daily dermal treatment with 1.1, 3.3 or 11.0 g/ kg of dimethyl sulfoxide (DM80) as a 90% solution in distilled water. The dogs were treated for 118 consecutive days, whereas the monkeys were treated for 185 to 200 consecutive days. In both species continued treatment produced a malodorous breath and desquamation at the site of dermal application but no changes in hematology, hemochemistry or urinalysis, except for enhanced 24-hour urine volumes, decreased urinary specific gravity and enhanced urinary excretion of hydroxyproline in some groups of monkeys. Treatment of the dogs produced slowly developing changes in the eye, manifested by myopia and lenticular changes ; when treatment was stopped and the animals were observed over the subsequent 71 to 92 days, there was no recovery from the dimethyl sulfoxide-induced eye changes, although the odor on the breath and the dermal lesions disappeared. Treatment of the monkeys for 185 to 200 consecutive days produced no ocular changes. The effects of dimethyl sulfoxide upon the eye, upon the kidney and upon hydroxyproline metabolism are discussed.