Essential fatty acid deficient rats in the study of cystic fibrosis: an X-ray microanalytical and ultrastructural study in chronically reserpinized rats.

Essential fatty acid (EFA) deficiency has been proposed as a major pathogenic mechanism for cystic fibrosis (CF) and EFA-deficient animals have been proposed as an animal model for CF. In the present study, the elemental composition and ultrastructure of the acinar cells of the submandibular and parotid gland of the pancreas of EFA-deficient rats were investigated by X-ray microanalysis and electron microscopy. The effects of EFA-deficiency were compared to changes in these exocrine glands in chronically reserpine-treated rats, an established animal model for CF. EFA-deficiency did not cause any significant changes in the elemental composition of the acinar cells of the submandibular or parotid gland, or of the pancreas. The changes in elemental composition induced by reserpine treatment were only slightly modified by EFA-deficiency, mainly towards normalization. EFA-deficiency resulted in the presence of abnormal, electron translucent, zymogen granules in the parotid gland and in a reduction of the number of zymogen granules in pancreatic acinar cells. Since EFA-deficiency in rats only causes minor changes in structure and elemental composition of salivary glands and pancreas, and does not potentiate the effect of chronic reserpine treatment on these tissues, it is concluded that EFA-deficiency is likely to be of minor importance in the exocrine gland disturbances in CF.