Behavioral Pharmacological Effects Of Mice After Interacerebroventricular Inject Peptide A

Peptide A is an endogenous ligand for a G protein-coupled receptor. The distribution of the Peptide A and their receptors are widespread in tissues. Peptide A has multiple biological effects such as lowering blood pressure, increasing cardiac contractility, regulating body fluid homeostasis, enhancing pituitary hormone release and modulating immunization. Peptide A system has been the significant target in new drug development.The behavioral pharmacological effects were investigated after micro-injecting Peptide A into lateral cerebral ventricles of mice.In the elevated plus-maze test, after micro-injecting Peptide A into lateral cerebral ventricles, Peptide A (100μg) significantly increased the percentage of open arm entries and of time spent in open arms. In the light/dark transition test, Peptide A (50, 100μg) increased the time spent in light area of the mice, while Peptide A (100μg) prolonged the latency time of mice getting into the dark area. In the tail suspension test, Peptide A (50, 100μg) produced a significant reduction in immobility, and the effect is dose-dependent, and Peptide A (25,50, 100μg) reduced the duration of immobility in the forced swimming test. In general, the results seen above indicate that Peptide A, at the doses in this paper, had anxiolytic properties in different anxiety models. In additional, Peptide A decreased the immobility in the behavior despair model in the mice, it suggest that Peptide A had the antidepressant effect.Peptide A (25,50, 100μg) enhanced learning and memory ability on the elevated plus-maze. In the locomotor activity test, Peptide A did not significant change locomotor activity of the mice. Moreover, under the dose in the test, Peptide A did not impair the muscle coordination in the rota-rod test.In conclusion, these findings indicate that Peptide A exhibits antixiolytic-like and antidepressant effects at given dosage.