Placental transfer andtissue distribution of "4C-styrene: an autoradiographic study inmice

Thedistribution of'4C-styrene wasstudied inthepregnant mouse using awhole bodylow temperature autoradiographic technique. Inunsectioned tissues studied byliquid scintillation the concentrations ofstyrene anditsmetabolites inmaternal andfetal bloodandorgansandinthe placenta andamniotic fluid weredetermined. Theorganswhich hadhigher concentrations ofvolatile styrene were maternal lung, kidney, liver, adipose tissue, andbrain inmicekilled shortly after injection. Non-volatile metabolites were localised inthelung, liver, kidney, gall bladder, and intestine. There wereconsiderable amountsofradioactivity inthefetuses, though theconcentrations werenotashighinthematernal tissues. Fetal tissue levels werealmost the same asmaternal brain in micekilled fromonetosixhours after injection. Theconcentrations ofstyrene andits metabolites in placenta andamniotic fluid wereabout twice those inthefetal tissues. Theplacenta seemstoplay the partofabarrier forthefetus. Because oftheir extensive use, organic solvents have received muchattention inthepastdecade aspossible factors incausing embryotoxic effects inman.Oneof these, styrene, plays animportant commercial part as ithasbeenusedintheproduction ofpolymers, copolymers, andreinforced plastics thathavebeen usedasfoodpackaging materials.'2 Styrene hasbeenreported tobemutagenic inmany experimental systems whenmetabolically activated3; toxicity andteratogenicity havebeenreported inchick embryos,4 butthere isonlyonereport onthefetal uptake anddistribution ofstyrene.5 Inviewofthecurrent interest inthetoxicology of styrene andthelackofquantitative dataon its distribution inthefetus wehavestudied thedistribu- tionof'4C-styrene using a wholebodylowtem- perature autoradiographic technique toassess thefetal uptake anddistribution after injection todams. Methods AUTORADIOGRAPHY (8-'4C)-Styrene witha specific activity of2-2m Ci/mmol waspurchased fromtheRadiochemical Centre, Amersham, UK,anddissolved insufficient styrene toobtain aconcentration of1pCi/pl. Themice