SR 57227 hydrochloride(SR 57227A ) is a potent, orally active and selective 5-HT3 receptor agonist. It with ability to cross the blood brain barrier. It has affinities (IC50) varying between 2.8 and 250 nM for 5-HT3 receptor binding sites in rat cortical membranes and on whole NG 108-15 cells or their membranes. Anti-depressant effects.

Seizure latency was significantly prolonged by a 5-HT3 receptor agonist SR 57227 in a dose-dependent manner.?Seizure score and mortality were also decreased by SR 57227 in PTZ-treated mice.?Furthermore, these anticonvulsant effects of SR 57227 were inhibited by a 5-HT3 receptor antagonist ondansetron.?However, ondansetron alone had no effect on seizure latency, seizure score or mortality at different doses.?Immunohistochemical studies have also shown that c-Fos expression was significantly increased in hippocampus (dentate gyrus, CA1, CA3 and CA4) of PTZ-treated mice.?Furthermore, c-Fos expression was significantly inhibited by ondansetron in mice treated with PTZ and SR 57227.?An ELISA study showed that SR 57227 attenuated the PTZ-induced inhibitory effects of GABA levels in hippocampus and cortex, and the attenuated effects of SR 57227 were antagonized by ondansetron in hippocampus but not cortex.?Activation of 5-HT3 receptor by SR 57227, which plays an important role on the control of seizure induced by PTZ, may be related to GABA activity in hippocampus.?Therefore, 5-HT3 receptor subtype is a potential target for the treatment of epilepsy[1].