ATRIAL-NATRIURETIC-PEPTIDE AND BRONCHIAL HYPERRESPONSIVENESS IN PATIENTS WITH MITRAL-STENOSIS

Atrial natriuretic peptide (ANP) has been reported to have protective effects against methacholine-induced bronchoconstriction in asthmatics . The aim of the study was to evaluate the relationship between plasma ANP levels and bronchial responsiveness to methacholine in patients w ith mitral stenosis. In 12 patients with moderate mitral stenosis, age 35-58 years, 9 female, 8 in NYHA class 2,4 in NYHA class 3 for sympto ms, plasma ANP and bronchial threshold to methacholine (PD20FEV1) were determined. The same measurements were performed in 10 asthmatic pati ents, hyperresponsive to methacholine, and in 10 normal subjects, nonr esponsive to methacholine. Mean +/- SE plasma ANP levels were signific antly higher in patients with mitral stenosis in comparison with asthm atics and normals (159 +/- 41.8, 7.3 +/- 0.98, 7.6 +/- 1.3, respective ly, p < 0.01). In patients with mitral stenosis there was a significan t relationship between plasma ANP and PD20FEV1 (r = 0.81, p < 0.01). N o relationship was found between ANP and PD20FEV1 in asthmatics. In co nclusion, in patients with mitral stenosis ANP seems to play a protect ive role against bronchial hyperresponsiveness to methacholine.