Cystic fibrosis - ultrastructural and microanalytical studies.

This review summarizes the contribution of electron microscopy and X-ray microanalysis to the study of the pathogenesis and the diagnosis of cystic fibrosis (CF). Light and electron microscopical studies of the most severely affected exocrine glands of CF patients (pancreas, tracheobronchial submucosal glands) generally show dilatation of the ducts and inspissation of mucous material. The ultrastructure of the acinar cells, however, is normal. Functional abnormalities in the gland can be demonstrated by X-ray microanalysis of the secreted fluid. In the search for the basic defect in CF use is often made of cultured fibroblasts. The ultrastructure of CF fibroblasts is basically normal. X-ray microanalysis shows significantly lower Na and higher Ca levels in CF fibroblasts. Several of the biological effects of the 'CF factor(s)', supposedly present e.g. in the serum of CF patients or in CF fibroblast culture medium, can be demonstrated by electron microscopy or X-ray microanalysis. Ultrastructural and X-ray microanalytical studies of 'animal models' for CF have shown that pathological changes in exocrine glands resembling some of those seen in CF patients, can be induced by interference with the nervous regulation of exocrine secretion.