SERUM ANGIOTENSIN-CONVERTING ENZYME-ACTIVITY IN PULMONARY-DISEASES - CORRELATION WITH LUNG-FUNCTION PARAMETERS

Serum angiotensin converting enzyme activity (ACE), plasma renin activ ity (PRA), blood pressure (BP), blood pH, blood gases and lung functio n parameters were measured in patients with emphysema, extrinsic and i ntrinsic asthma, malignant pulmonary neoplasms, active sarcoidosis and healthy adults. Serum ACE activity was significantly higher in sarcoi dosis (250.22 +/- 34.18 U/L); in small cell carcinoma of lung (155.10 +/- 38.25 U/L); emphysema (149.82 +/- 18.31 U/L), extrinsic asthma (14 1.22 +/- 25.30 U/L) and lower in intrinsic asthma (98.12 +/- 15.11 U/L ) and squamous cell carcinoma of lung (97.29 +/- 18.85 U/L) when compa red with that of control subjects (108.20 +/- 13.15 U/L). PRA and BP v alues of the patients with sarcoidosis, emphysema and small cell carci noma were markedly elevated and sACE activity was found to be correlat ed with PRA and mean BP in the same diagnostic groups, sACE activity, PRA and BP of smokers were higher than those of non-smokers in-control subjects and in patients with emphysema, extrinsic asthma and small c ell carcinoma of lung. Oxygen tensions of the patients with emphysema, extrinsic asthma and small cell carcinoma of lung were found to be sig nificantly decreased. Negative correlations between the sACE activity and oxygen tension (r = -0.68) and between the sACE activity and lung function parameters (r = -0.69) were found in these diagnostic groups suggesting that increased sACE level might appeared as a response to c hronic hypoxia in the patients with emphysema, extrinsic asthma and sm all cell carcinoma of lung.