Abstract:Aims] Beta-endorphin has been known as a mediator of runner's high.However, previous studies demonstrated that the endogenous cannabinoids (eCB), such as 2-Arachidonoylglycerol (2AG) and anandamide ar...Aims] Beta-endorphin has been known as a mediator of runner's high.However, previous studies demonstrated that the endogenous cannabinoids (eCB), such as 2-Arachidonoylglycerol (2AG) and anandamide are stronger effecter on runner's high.In addition, the affinity of 2AG and cannabinoid receptor type 1 is higher than the anandamide, the 2AG may stronger mediator of exercise induced euphoria.Recent study shows that blood concentration of 2AG is increased under stress conditions, but it is not clear whether a bout of exercise increase the blood 2AG concentration.This study investigated whether the ventilatory threshold intensity exercise increases blood 2AG concentration.[Methods] Eleven men (38±17 years) without exercise habits and medication were participated in this study.Blood sample was collected from earlobe before and after the 60-minute pedaling exercise.The concentrations of 2AG and 1-Arachidonoylglycerol (1AG) were measured using LC-MS/MS.Because 2AG is rapidly isomerized to 1AG, the sum of these values was used as plasma concentration of 2AG.[Results] The 2AG + 1AG was significantly increased after exercise (Before: 21.7 ± 8.2 ng/mL, After: 32.5 ± 16.1 ng/mL, p < 0.01), and the concentrations was increased after exercise in all subjects.The changes of 2AG + 1AG is correlated with the %HRR during exercise (r = 0.79, n = 11, p < 0.01).[Conclusions] Low intensity exercise could increases blood 2AG concentration.Read More