ABSTRACT
Discovery Research Laboratories I, Research Division, Sumitomo Pharmaceuticals Co., Ltd., 3-1-98 Kasugade-naka, Konohana-ku, Osaka 554-0022, Japan
Abstract-Antiparkinsonian effects of tandospirone, a selective 5-HTJA receptor agonist, were evaluated using rat models of Parkinson's disease. Tandospirone reversed catalepsy induced by the D2 antagonist haloperidol, in a dose-dependent manner. The anti-cataleptic action of tandospirone was comparable to that of bromocriptine and greater than that of L-DOPA. In rats with unilateral dopaminergic lesion by 6-hydroxydopamine, tandospirone markedly induced contralateral rotation. Furthermore, tandospirone dose-dependently restored spontaneous locomotor activity in reserpinetreated rats. These antiparkinsonian effects of tandospirone were abolished by coadministration of WAY-100635, a selective 5-HTIA antagonist, but not by haloperidol. The present results suggest that tandospirone has a therapeutic potential in treating parkinsonian symptoms, which is brought about through activation of 5-HTIA receptor.
