Ultrastructural observations by scanning electron microscope (SEM) of preor neoplastic tracheal lesions in Syrian golden hamsters induced by diethylnitrosamine (DEN) were investigated. Twenty five, six-week-old, male Syrian golden hamsters were injected subcutaneously twice a week for 12 weeks with 18mg/kg body weight of DEN. Six hamsters were injected only vehicle and served as control. At wee...
