The Japanese Teratology Society NII - Electronic Library Service

Palatal primordia of day−1251CR mouse fetuses were cultured in a chemi − ca】[ydefined serumless medium by a suspension cuhure technique, and the developmental tQxicity of aspirin and its metabolites on in vitro pa was studied . Explanted fetal palates were exposed in vitro for 72 hr to O,5−2 mM aspirin (ASP),025 −2 mM salicylic acid (SA ),0.5−2 mM salicyluric acid (SUA ),1−2 mM 2,3−dihydroxybenzoic acid (3DHB ), or 1−2 mM 2,5−dihydroxybenzoic acid (5DHB ), After 72 hr culture , ASP at 2 mM and SA at O.25 mM inhibited the growth and fusion of palatal shelves , and SUA at lmM prevented palatal fusion. On the other hand,3DHB and 5DHB did not exert any significant toxic effects on cultured palates at concentrations up to 2 mM . Judging from the 50 % inhibitory concentration (IC50), SA (IC50 = 0,9 mM )was the most toxic of the 5compounds tested, with a decreasing order of ASP (IC50 = 1.5 mM ), SUA (IC50=1.6 mM ), and DHBs (IC50 = over 2 mM for both 3DHB and 5DHB ). With respect to develop− mental texicity , cultured fetal mouse palates showed the susceptibility to aspirin and its metabolites which is intermediate between the susceptibility of rat embryos in vivo and that of postimplantation rat embryos cultured in レitrv . The significance of fetal organ culture fbr evaluating deve]opmental toxicity of chemicals is also discussed .