REDUCED DIAZEPAM BINDING FOLLOWING CHRONIC BENZODIAZEPINE TREATMENT

Specific 3H-diazepam binding was measured in rat cortex after 7-10 days of twice daily injection of a large dose of flurazepam. Compared to cortex taken from saline treated controls, there was a statistically significant decrease of about 15% in the maximum binding capacity (Bmax). There was also a change in the dissociation constant (KD) from 5.27 to 8.80 nM. Repeated washing of the tissue sample before the binding assay showed that the Bmax was truly decreased in the treated animals, but the change in KD was probably an artifact due to residual flurazepam remaining in the tissue that interfered with the binding assay. It is concluded that chronic benzodiazepine treatment caused an apparent decrease in the number of specific binding sites. © 1978.