Ultrastructure of bronchial submucosal glands in children with chronic respiratory diseases.

The ultrastructure of bronchial submucosal glands in 4 children with chronic respiratory diseases was studied. Based on their ultrastructure the glandular secretory cells were divided into four categories: 1. mucous cells packed with large electron-lucent coalescing granules with fibrogranular matrix, 2. mucous-like cells with abundant granular endoplasmic reticulum and fewer smaller electron-lucent granules, 3. serous cells containing small to moderately large membrane-bound electron-dense granules with homogenous matrix and prominent granular endoplasmic reticulum, 4. sero-mucous cells similar to the serous ones but containing granules of either serous or mucous morphology. In our patients the mucous and mucous-like cells prevailed, forming 54.6%-100% of the glands' secretory area. Only in 2 children all four types of secretory cells were detected. Signs of pathological alteration were discovered in secretory cells of all patients. The system of intra- and interlobular ducts was lined by tall mucous cells.