EARLY DECREASE IN DENSITY OF MONONUCLEAR LEUKOCYTE BETA-ADRENOCEPTORS IN DEPRESSED-PATIENTS FOLLOWING AMINEPTINE TREATMENT - POSSIBLE RELATION TO CLINICAL-EFFICIENCY

1. The effect of chronic amineptine treatment (200mg/day) on beta-adrenoceptor density of intact mononuclear leukocytes (MNL) was examined in unmedicated major unipolar depressed patients. 2. Pretreatment parameters of (-)-[I-125]-iodopindolol specific binding did not differ significantly from age- and sex-matched healthy controls as the patients were only moderately depressed. 3. All patients showed a highly significant clinical improvement as assessed by the AMDP-depression scale after one week of amineptine (D7), while 2 patients relapsed after one month of treatment (D28) and were considered to be non-responders. 4. The maximal density of beta-adrenoceptors (Bmax) was significantly decreased at D7 (by 33%) compared to pretreatment level (D0) in the treatment responders and remained lower at D28, although the difference was no longer significant. No alteration in beta-receptor affinity (Kd) was detected during the treatment. 5. These results indicate that treatment with amineptine, an anti-depressant drug known to selectively inhibit the dopamine uptake system, can rapidly affect MNL beta-adrenoceptors. 6. Moreover, the present findings show that the reduction in MNL beta-adrenoceptor density, which is associated with a stable clinical improvement, may provide a predictive index for successful anti-depressant treatment.