Influence of chlorpromazine on the rabbit electroretinogram.

In anesthetized albino or nonalbino rabbits, a 3 to 8 mg/kg IV injection of chlorpromazine did not affect a-wave amplitude of the electroretinogram (ERG). However, immediately after the injection of the drug, b-wave amplitude increased. The maximum increase occurred between 35 to 50 min, and the recovery time varied between 5 to 8 hr. Initial changes in the b-wave amplitude to some extent were affected by systemic changes in the blood pressure. However, the b-wave amplitude remained high for a long time after the blood pressure reached preinjection value, indicating a local effect of the drug. There was no change in a- or b-wave latencies. Although in vitro a large quantity of chlorpromazine can be localized in the melanin granules from pigmented rabbit retina, in vivo the ERG b-wave changes caused by the small intravenous dose of the drug were similar in both albino and nonalbino rabbits.