[Chronic pneumonia and cancer: changes in beta-adrenergic receptors in human lung parenchyma]

beta-Adrenergic and muscarinic cholinergic receptors have been investigated in human lung parenchyma during cancer and chronic pneumonia as compared with normal tissue, obtained after segmental resection of tuberculoma from surrounding normal tissues. Binding of beta-adrenergic radioligand 3H-dihydroalprenolol (3H-DHA) and muscarinic antagonist 3H-quinuclidinyl benzylate (3H-QNB) was saturating with high rate of affinity in lung parenchyma membranes of both controls and patients with cancer and chronic pneumonia. Amount of binding sites of 3H-QNB was significantly increased in cancer (Bmax = 377.5 +/- 65.5 fmole/mg) and did not change in chronic pneumonia (Bmax = 97.7 +/- 14.7 fmole/mg) as compared with normal tissues (Bmax = 108.9 +/- 12.1 fmole/mg); a number of binding sites of 3H-DHA was significantly decreased both in lung parenchyma under conditions of cancer (Bmax = 84.1 +/- 14.5 fmole/mg) and chronic pneumonia (Bmax = 113.8 +/- 10.3 fmole/mg) as compared with normal tissue (Bmax = 456.7 +/- 73.7 fmole/mg). The affinity of 3H-DHA and 3H-QNB binding was practically unaltered. The results obtained suggest the important role of beta-adrenergic receptors in formation of lung cancer in the patients with pneumonia.