Guanosine ameliorates positive symptoms of schizophrenia modulating 5-HT and 5-HT receptors.

Schizophrenia is a serious mental disorder characterized by hallucinations, delusions, and extremely disordered thinking and behavior. There are several hypotheses of pathogenesis in schizophrenia: dopaminergic, glutamatergic, or serotonergic hyperfunction. Guanosine reportedly protects the central nervous system by modulating the glutamatergic system. Thus, we assumed that guanosine may exert a positive effect on the pathophysiology of schizophrenia. Herein, we demonstrated that guanosine significantly reduced MK-801-induced hyperlocomotion and stereotyped behaviors, but showed no effect on hyperlocomotion induced by d-amphetamine, indicating that guanosine may directly affect the glutamatergic system. Guanosine dose-dependently reduced 5-HTP-induced wet dog shakes (WDS) and other serotonin syndromes (SS) behaviors, indicating that it might block serotonin 5-HT or 5-HT receptors. Finally, we confirm that that guanosine modulates serotonin 5-HT and 5-HT receptors and it might be anti-schizophrenic partly through pertussis toxin-sensitive G-coupled PI3K/Akt signaling. Collectively, this study provides possible compounds and mechanisms for therapeutic effects on schizophrenia.