Efficacy of Hydroquinone in the Treatment of Cutaneous Hyperpigmentation in Hairless Descendants of Mexican Hairless Dogs Xoloitzcuintli)

摘要

Theskinofadulthairlessdogsisclinicallynonpigmented,clinicallylightlypigmented,orclinicallyhyperpigmented(spottypigmented).Thepigmentnotedclinicallyisattributabletomelaningranulesintheepidermis.Spottypigmentationintheskinofadulthairlessdogswastreatedbyadministrationofthedepigmentingagent(3%hydroquinone,HQ)for1month.Depigmentingeffectswereexaminedbyuseofthreemethods:skincolor,dihydroxyphenylalanine(DOPA)-positivemelanocytecount,andhistologicevaluation.ThetreatedskinofhairlessdogsbegantobecomedepigmentedafterapplicationofHQfor1week.After1monthoftreatmentwithHQ,depigmentationspreadoveraquarterofthebody.ThenumberofDOPA-positivemelanocytesintheHQ-treatedsitesdecreasedtolessthanapproximatelyafifthofthatbeforetreatment.InHQ-treatedskin,histologicstainingbyuseofFontana-Masson's(FM)methodrevealedcompleteabsenceofmelaninpigment.Theseresultssuggestedthathairlessdogsshouldbeausefulanimalmodelforinvestigatingtheeffectsandcutaneoustoxicityofdepigmentingagents.