Changes in the affinity of [3H]nimodipine binding sites in the brain upon chlorpromazine treatment and subsequent withdrawal.

Male mice were chronically treated with chlorpromazine mixed in powdered diet, and the properties of brain calcium channels were assessed using [3H]nimodipine binding. It was found that this treatment resulted in a significant increase in the affinity of calcium channels, without a significant change in their density. These effects of chlorpromazine were time dependent. When mice were administered chlorpromazine for 2 months, then the drug was withdrawn, there was a rebound decrease in the channel affinity.