Abstract: AIM To explore whether alarin, a new member of the galanin family, elicits a regulation on the cardiovascular system and to provide experimental evidence for the understanding of the biological effect of galanin protein family. METHODSThree types of alarin (1-25, 3 -25, 6-25) were synthesized by Kofler Laboratory in Australia and two domestic companies. Animals were randomly divided into two groups including positive control group (norepinephrine, NE group) and experimental group (alarin group). The effects of alarin on cardiac function, blood pressure, heart rate, and vascular tension were determined through animal experiments in vivo and vascular reperfusion experiments in vitro, respectively. RESULTSDifferent doses of alarin elicited no significant effect on blood pressure, heart rate and vascular tension. Synthetic alarin (1-25, 3-25, 6-25) from three companies at different doses had no significant effect on cardiac function, and the final concentration of alarin at 1, 2, 5, 10 mol/L had no effect on the tension of abdominal artery. NE produced a significant increase in cardivascular function. CONCLUSIONThe present study demonstrates that alarin alone may have no functional regulation on the cardiovascular system.