G-PROTEIN LEVEL QUANTIFICATION IN PLATELETS AND LEUKOCYTES FROM PATIENTS WITH PANIC DISORDER

The objective of our study was to investigate if there ave abnormaliti es in signal transducing G proteins in patients with panic disorder We utilized selective antibodies to quantitate the levels of the G prote in a subunits that regulate adenylyl cyclase activity (G alpha(s) and G alpha(i2)) and phosphoinositide turnover (G alpha(q/11)) in platelet membranes (and leukocyte membranes for G(alpha s)), and also carried out pertussis toxin (PT) catalyzed [P-32]ADP-ribosylation in platelet membranes from a group of 13 untreated panic disorder patients, 10 unt reated social phobia patients, and 12 healthy subjects. There were no significant differences among the three groups in the immunolabeling o f G alpha(a) in platelets or leukocytes, or in the immunolabeling of G alpha(i1/2), G(alpha/11), or PT-catalyzed [P-32]ADP-ribosylation in p latelets. Within the constraints imposed by using peripheral blood cel ls to reflect brain composition, our results do not provide support fo r G protein abnormalities in patients with panic disorder. These resul ts contrast with those obtained rising identical methodology in bipola r affective disorder, where elevated G(alpha s) in leukocytes has been reported (Manji et al. 1995).