REGENERATION OF INJURY OF THE RABBITS (ORYCTOLAGUS-CUNICULUS VAR EDULIS) TRACHEAL EPITHELIUM DUE TO THE INTRATRACHEAL ADMINISTRATION OF AN IODINATED CONTRAST AGENT

Ultrastructure of the rabbits' tracheal epithelium was studied 24 and 48 hours after intratracheal administration of 1 ml of iopamidol. Twen ty four hours post exposure the ciliated cells revealed only mild sing s of pathological alteration, the goblet cells were overstimulated, 87 +/- 1% of them were completely exhausted and degenerated. Layers of i nspissated mucus embedding kinocilia presented signs of self-cleaning ability impairment. Highly condensed masses of iopamidol were encounte red in the granulocytes and in a few phagocytic vacuoles in the ciliat ed cells' cytoplasm. Forty eight hours post exposure the differentiati ng secretory elements presented 60% of all secretory cells. The cells with isolated small electron-dense granules, typical serous-like cells and small mucous granule cells were observed. The contrast agent was completely removed from the epithelium. Only isolated small clusters o f inspissated mucus were encountered in the area of the ciliary border . The damage to the airways' epithelium due to the iopamidol administr ation was not repaired completely in the course of 48 hours.