Ciliated cells of the trachea of the rabbit, treated with cis-diamminedichloroplatinum (II) alone, or in combination with ionizing radiation.

Abstract

The ciliated epithelium of the rabbit trachea was irradiated with daily fractions of 2 Gy to an accumulated dose of 20 Gy (TD: 2, 6, 10, 16, or 20 Gy). Fifteen to forty-five minutes before start of the first irradiation (treatment day 1), 5 mg cis-DDP was given by intraperitoneal injection to each rabbit. Examination was made 1 - 10 days after each fractionation schedule, when specimens were taken for investigations. Scanning electron microscope investigations showed a gradual development of ciliary damage from blebs on the cilia to swollen tips, broken and bent cilia and finally an epithelial lining with areas free from cilia with a surface covered with microvilli-like structures. SEM also showed cell loss, and remnants of dead cells on the surface together with detritus. By transmission electron microscope ciliary damage, cell death and cell loss of the ciliated cell layer as well as exfoliation of portions of goblet-like cells on the surface could be confirmed. The irradiated ciliated epithelium and the untreated control epithelium in each animal showed no difference in this respect. Thus no enhancement of the effects of radiation could be observed. The development of ultrastructural damage may be due to a cytotoxic effect of the drug on the ciliated epithelium. However, 19 days after the start of cis - DDP injection, a hyperplasia of the basal cell layer was observed, which indicates that the observed cytotoxicity of the drug is reversible and a normalisation occurs during the last days of observation in this study.