Peculiarities of Purinergic Modulation of Myoneural Transmission in Presence of Capsaicin

Abstract

This study aimed to investigate myoneural transmission in the presence of capsaicin that acts as an “integrator of painful stimuli and causes heat sensation”. The effects of purines such as ATP and adenosine that participate in synaptic transmission in presence of capsaicin have been explored. When the muscle-nerve preparation of frog was perfused with solution containing capsaicin, the inhibitory effects of both purines were significantly reduced. A reduction of the depressant effects of adenosine is associated with the inhibition of A1 signaling, since the A2A receptor agonist CGS21680 showed pronounced, almost completely hidden in the control, potentiating effect in presence of capsaicin. Our findings suggest that the known neuroprotective effect of capsaicin is primarily due to elimination of inhibition by endogenous purines of the induced quantum output of the neurotransmitter.