Salivary electrolytes in fibrocystic disease of the pancreas.

There has been considerable work in recent years showing that other exocrine glands, in addition to those secreting mucus, are affected in fibrocystic disease of the pancreas. In 1951, Kessler and Andersen showed that patients with fibrocystic disease of the pancreas are particularly liable to heat prostration during hot weather. In 1953, di Sant' Agnese, Darling, Perera and Shea reported that the sweat of fibrocystic patients contained abnormally high values for sodium and chloride, and these findings were confirmed by Shwachman, Leubner and Catzel (1955). In their original article, di Sant' Agnese et al. stated that not only are the sweat glands involved in fibrocystic disease of the pancreas, but there is evidence also that the parotid secretory rate is increased, and that the values for sodium and chloride in mixed saliva are elevated. Prader, Gautier, Gautier and Naef (1955) showed that the sodium content of mixed saliva is dependent on the rate of flow of saliva, the duration of collection and the time of day of collection. They found that when all these factors were carefully controlled they were able to obtain constant results. Prader and Gautier (1955) also report that the sodium concentration of mixed saliva obtained by aspiration was increased in eleven children with cystic fibrosis of the pancreas. McGrady and Bessman (1955) found that the chloride concentration of saliva varied greatly with the method of collection, and that consistent results were obtained only with parotid secretion. In five patients with mucoviscidosis the chloride content of parotid saliva was markedly elevated as compared with 100 controls. The present study was undertaken to analyse the parotid secretion for electrolyte content in a number of patients with fibrocystic disease of the pancreas attending The Hospital for Sick Children, Great Ormond Street. Method The parotid secretion was obtained by placing a small metallic collecting device over the orifice of Stenson's duct. The device was made to adhere to the surrounding mucous membrane by suction, and the parotid saliva, uncontaminated by other salivary secretions, was easily collected. In all cases, a few crystals of citric acid were placed on the tip of the patient's tongue in order to stimulate the salivary flow. The parotid secretion was collected for a period of one minute after the onset of flow, and usually O4 ml. or more of fluid was obtained. Occasionally, the collection lasted more than one minute in order to obtain a sufficient amount of secretion. In each case, the volume of fluid was carefully measured together with the length of time of collection. The secretions were analysed for sodium and potassium concentration by flame photometry, and for chloride concentration by the method of Van Slyke and Hiller (1947). Parotid secretion was analysed by this method in 31 patients with proven fibrocystic disease of the pancreas. Sixty-three patients with various diseases in the wards of the hospital served as controls. The average age of the fibrocystic group was 6 years, with a range from 2 to 14 years. The average age of the controls was 8 years, with a range from 2 to 12 years. The fibrocystic group consisted of 14 males and 17 females, and among the controls there were 24 males and 39 females.