Ultrastructure of cultivated fibroblasts in cystic fibrosis of the pancreas

Abstract

Cultivated fibroblasts from patients with cystic fibrosis of the pancreas and from control individuals were investigated by electron microscopy. In both groups, the cytoplasmic granules which by light microscopy were metachromatic appeared in electron micrographs to consist of membrane-bound bodies (lysosomes) containing a variable amount of material compatible with ultrastructural features of phospholipids and mucopolysaccharides. The only difference was quantitative: Cells from patients contained larger and more numerous lysosomes than control cells. On the basis of such findings it is proposed that many tissues in cystic fibrosis are affected by a common defect which impairs cell transport mechanisms and membrane permeability and which can be enhanced in tissue culture. As a result, excessive amounts of metabolites would accumulate in the cells, stimulating lysosomal activity.