StudyofClosure oftheEmbryonic RatPalate InVitro with theEffects ofCertain Chemicals

Inorgancultures ofrat-palatal processes from15-day-old embryos, addition ofvitaminA orvitamin A withcortisone tothe culture mediumcaused nonfusion andepithelial disruption. Cortisone alonedidnot showateratogenic effect; nordiditexaggeratetheeffect ofvitamin A. Theclosure ofthepalatal processes inthe embryonic rathasbeenstudied insomedetail,' including several invitro studies.36 Theselatter reports havedemonstrated that organculture isa validmethodforthe study ofnormal orabnormal palatal closure. However, intheliterature, there waslittle information pertaining totheaddition of teratogenic agents totheculture mediumof suchdeveloping ratpalates. Because ofthe importance oftheeffects ofvarious drugs ondevelopmental processes andbecause of theavailability oftheunique tooloforgan culture, thisinvestigation wascarried out. Materials andMethods