CAS：152685-85-3 HEMORPHIN-7 TYR-PRO-TRP-THR-GLN-ARG-PHE HEMORPHIN-7

LVV-hemorphin-7 (LVV-h7) is a bioactive peptide resulting from the degradation of hemoglobin β-globin chain. LVV-h7 is a specific agonist for the angiotensin IV receptor. This receptor belongs to the insulin-regulated aminopeptidase (IRAP) class and has oxytocin activity. Here, we aim to evaluate: i) whether LVV-h7 alters the behavior of concentrated tissues and cardiovascular response to stress, and ii) the underlying mechanism of LVV-h7 effects involves activation of the oxytocin (OT) receptor, which may be the result of reduced IRAP proteolytic activity during overtime. Adult male Wistar rats (270 -- 370 g) received (ip) LVV-h7 (153 nmol/kg) or the carrier (0.1 ml). Different protocols were used: i) Open Field (OP) testing for sports/exploration activities; ii) Elevated Cross mazes (EPMs) for anxiety-like behavior; iii) Forced swimming test (FST) test for depression-like behavior and iv) air injection for cardiovascular response to acute stress exposure. Diazepam (2 mg/kg) and imipramine (15 mg/kg) were used as positive controls for EPM and FST, respectively. OT receptor (OTr) antagonists atosiban (1 and 0.1 mg/kg) were used to determine the involvement of the oxytocin pathway. We found that LVV-h7: i) increased the number of entries and time spent in the maze with open arms, which indicated anti-anxiety; ii) Stimulating antidepressant effects in FS tests; iii) Increased exploration and movement; iv) did not alter cardiovascular and neuroendocrine responses to acute stress. In addition, increased exercise and LVV-h7 induced antidepressant effects were restored by OTr antagonists. We conclude that LVV-h7 modulates behavior shown in part by the oxytocin receptor.