Studies on induction of polydactyly in rats with cytosine arabinoside☆

[摘要] Cytosinearabinosideadministeredatappropriatetimesproducedpolydactylyoftheforelimb(d.10)andrearlimb(d.11)intheoffspringofpregnantrats.Attemptstodefinethemechanismwherebyanantiproliferative,cytotoxicagentcouldproducepolydactylycenteredonexaminationofproliferativerateintherearlimbfollowingaregimenknowntoproducerearlimbpolydactylyin85%ofsurvivingfetuses.Tissuesfor[3H]thymidineautoradiographyweretaken9–42hrfollowingdrugadministration.Incontrolembryos,mesodermalcellsinvariousregionsofthelimbappearedtoproliferateatuniformratesuntilthe13thdaywhentheproximalfieldsbegantoshowdiminishedactivity.Likewise,pre-andpostaxialectodermofthelimbseemedtobeproliferatingatequalratesincontrolembryos.Apositivecorrelationinproliferativeratebetweentheectodermandmesodermwasfoundtoexistincontrolembryos,i.e.,asonetissueincreasedordecreasedinproliferativeactivitytheotherbehavedinsimilarfashion.Intreatedembryosthiscorrelationwasabsent.Treatedembryosalsorevealedcell-cyclesynchronyofbothmesodermalandectodermalcellsalthoughthetimeofpeakDNAsynthesiswasdifferentinthetwotissues.Histologically,cytosinearabinosideproducedcelldegenerationespeciallyinthemesoderm.Possiblyofmoreimportancewasthefindingofcelldeathinthepreaxialectodermofcontrolembryoslateonthe12thdayofdevelopment,whereastreatedembryosofasimilaragedidnotshowasimilarregionofdegeneration.

[学科分类] 生物科学（综合）