Correlation between neutral endopetidase (NEP) 3.4.24.11 in serum and the degree of the bronchial hyperreactivity

Neutral endopeptidase (NEP) is described in airways as the major degrading enzyme of tachykinins such as neurokinin A (NKA) and substance P (SP). Due to its localization and mode of action NEP may play a role in the pathophys iology of bronchial reactivity (BR) especially under the aspect of neurogen ic inflammation. Serum NEP concentrations were measured by ELISA to investi gate if there is a correlation between serum NEP and the degree of bronchia l reactivity expressed by PC20-FEV1 histamine. PC20-FEV1 histamine was dete rmined in 31 asthmatic patients [age 31.9+/-1.3 years (mean+/-SEM) FEV1 = 9 2.1+/-2.4% (mean+/-SEM) 16 females/15 males]. Prior to the histamine challe nge blood samples were obtained and stored at -70 degreesC until determinat ion using ELISA. A significant correlation between serum NEP and the PC20-F EV1 (n = 31, r = 0.49, P < 0.01) was found. The results suggest that serum NEP is modulating neuropeptide-induced effects in the pathophysiology of ai rway responsiveness. (C) 2001 Elsevier Science B.V. All rights reserved.