Alpha 1-acid glycoprotein concentration and molecular heterogeneity: relationship to oxprenolol binding in serum from healthy volunteers and patients with lung carcinoma or cirrhosis.

1. alpha 1-acid glycoprotein (AAG) concentration and molecular heterogeneity, and oxprenolol protein binding were studied in serum of 15 healthy volunteers, 14 patients with lung carcinoma and 17 patients with liver cirrhosis. 2. The AAG serum concentration was increased to 180.7% in patients with lung cancer and decreased to 73.4% in cirrhotic patients as compared with controls (P less than 0.05). 3. The concanavalin A (conA) dependent heterogeneity of serum AAG was very similar in controls and patients with lung cancer: a ratio of 9/9/2 was obtained for the conA nonreactive, the conA weakly reactive and the conA strongly reactive subfraction respectively; in cirrhotic patients, the ratio shifted to 11/7/1. 4. The heterogeneity in electric charge, demonstrated by isoelectric focusing, was similar in the three groups of subjects: 70-80% of the focussed bands were found in the main three bands. 5. The binding of oxprenolol to serum proteins was increased in lung tumour patients and decreased in liver cirrhotic patients as compared with controls (P less than 0.05). There was no change in binding affinity and oxprenolol binding was significantly correlated to total AAG serum concentration and to the concentration of each of the conA dependent subtypes, in controls as well as in both patients groups.