Congenital anomalies of the ear resulting from cyclophosphamide treatment in the rat.
A single dose of cyclophosphamide (20 mg/kg) administered on day 12 of gestation to CF rats resulted in microtia in 97.5% of fetuses at term. The ears of affected fetuses were low set and dorsally placed. Histological examination revealed persistence of meatal plug, branching of the primordium of external acoustic meatus, periotic hemorrhages, narrowing of tympanic cavity, presence of only one to two primordia of middle ear ossicles, hypoplasia of stapedial artery, a maximum of two turns of cochlea and under differentiation of the organ of Corti and the semicircular ducts. Hemorrhages in and around the region of the ear were extensive. Bilaterally symmetrical distribution of microtia and consistency of associated anomalies suggest that this is a good animal model for further investigation into the pathogenetic mechanisms of these ear anomalies.
D000818:Animals; D003520:Cyclophosphamide / Q000008:administration & dosage* / Q000494:pharmacology; D004423:Ear / Q000002:abnormalities*; D007758:Ear, Inner / Q000196:embryology / Q000473:pathology; D004432:Ear, Middle / Q000196:embryology / Q000473:pathology; D005260:Female; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats / Q000196:embryology; D011919:Rats, Inbred Strains
D003520:Cyclophosphamide