Local infusion of pyridoxine significantly reduced muscle sympathetic nerve activity and blood pressure responses to fatiguing handgrip compared to baseline, an effect not seen with saline.
Does local infusion of pyridoxine reduce muscle sympathetic nerve activity and blood pressure responses to fatiguing handgrip in young healthy volunteers?
P2 receptor blockade with pyridoxine attenuates the sympathetic and blood pressure responses to exercise in humans, suggesting P2 receptors contribute to the exercise pressor reflex.
During exercise, sympathetic nervous system activity increases and this contributes to an increase in blood pressure (i.e. exercise pressor reflex). Although animal studies suggest that purinergic P2 receptors on thin fibre sensory nerves are stimulated and evoke this reflex, human data are lacking. In this study, young healthy volunteers performed fatiguing isometric handgrip before and after a local infusion of pyridoxine (i.e. vitamin B(6)) into the 'isolated' circulation of the human forearm. Pyridoxine is converted into a P2-purinoceptor antagonist. Muscle sympathetic nerve activity and blood pressure responses to fatiguing handgrip and post-exercise circulatory occlusion were significantly less after pyridoxine than they were before. These effects were not observed after infusion of saline. These data suggest that P2 receptors contribute to the exercise pressor reflex in humans.
Cui et al. (Tue,) conducted a other in Healthy volunteers. Pyridoxine (vitamin B6) local infusion vs. Baseline (before infusion) and saline infusion was evaluated on Muscle sympathetic nerve activity and blood pressure responses to fatiguing handgrip and post-exercise circulatory occlusion. Local infusion of pyridoxine significantly reduced muscle sympathetic nerve activity and blood pressure responses to fatiguing handgrip compared to baseline, an effect not seen with saline.