Excretion of trypsin-like activity, electrolytes and protein in mixed and parotid saliva of patients with cystic fibrosis of the pancreas.

The esterolytic activity of mixed and parotid saliva in cystic fibrosis (CF) patients and normal subjects was determined using BAEE (alpha-Benzoyl-1-arginine-ethylester) as the substrate. Using soybean-trypsin-inhibitor the trypsin-like activity (TLA) was measured and plotted as a function of parotid flow rate. In addition calcium, protein and pH were determined. Trypsin-like activity in mixed and parotid saliva showed large individual variations in CF and normal children. In parotid saliva we could not find any significant difference, whereas a reduction of TLA in mixed saliva of CF patients was observed. The fact that our normal values fell within the range of heterozygotes reported by Rao et al. (19), makes their hypothesis of a close relationship between reduced TLA and the genetic defect very doubtful. Protein, calcium and pH increased with augmented salivation and no difference between CF patients and normal age matched children could be found except for the pH at a flow rate above 0.75 ml/min per m2 body surface where significantly lower pH values resulted. The relevance of reduced TLA to the pathogenesis of cystic fibrosis is discussed.