Brain neurotransmitter receptor-binding characteristics in rats after oral administration of haloperidol, risperidone and olanzapine.

Shinya Uchida, Yasuhiro Kato, Kazufumi Hirano, Yoshiyuki Kagawa, Shizuo Yamada

Department of Pharmacokinetics and Pharmacodynamics and Center of Excellence (COE) Program in the 21st Century, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.

Life sciences 2007 Apr 3

filter terms:

The present study was conducted to characterize the binding of neurotransmitter receptors (dopamine D(2), serotonin 5-HT(2), histamine H(1), adrenaline alpha(1) and muscarine M(l) receptors) in the rat's brain after the oral administration of haloperidol, risperidone, and olanzapine. Haloperidol at 1 and 3 mg/kg displayed significant activity to bind the D(2) receptor (increase in the Kd value for [(3)H]raclopride binding) in the corpus striatum with little change in the activity toward the 5-HT(2) receptor (binding parameters for [(3)H]ketanserin). In contrast, risperidone (0.1-3 mg/kg) showed roughly 30 times more affinity for the 5-HT(2) receptor than D(2) receptor. Also, olanzapine (1-10 mg/kg) was most active toward the H(1) receptor in the cerebral cortex, corpus striatum, and hippocampus, was less active in binding 5-HT(2) and D(2) receptors, and showed the least affinity for alpha(1) and M(1) receptors. In conclusion, haloperidol and risperidone administered orally selectively bind D(2) and 5-HT(2) receptors, respectively, in the rat brain, while olanzapine binds H(1), 5-HT(2), and D(2) receptors more than alpha(1) and M(1) receptors.

Citation

Shinya Uchida, Yasuhiro Kato, Kazufumi Hirano, Yoshiyuki Kagawa, Shizuo Yamada. Brain neurotransmitter receptor-binding characteristics in rats after oral administration of haloperidol, risperidone and olanzapine. Life sciences. 2007 Apr 3;80(17):1635-40