Central serotonin antagonist activity of ketanserin

Ketanserin, given i.p. 1 hr before quipazine, antagonized the elevation of serum corticosterone by quipazine in rats. The relatively low ED50 value of ketanserin (0.9 mg/kg) supports other literature data showing that ketanserin is selective for the 5HT2 subtype of serotonin receptors, the data also suggest that 5HT2 receptors are involved in the elevation of serum corticosterone by the serotonin agonist, quipazine.