Possible Interaction: Adenosine and Substance P

“During intrailiac infusion, all patients experienced pain in the right leg that occurred earlier (207 +/- 152 vs. 321 +/- 154 s, p < 0.05) and was greater (47 vs. 30 mm, p < 0.05) during the simultaneous infusion of substance P plus adenosine than during the infusion of adenosine.”

“OBJECTIVES This study investigated whether substance P potentiates the muscular and cardiac pain caused by the intraarterial infusion of adenosine , an autocoid known to induce muscular and cardiac ischemic-like pain in humans.”

“Similarly, during intracoronary infusion, all patients experienced chest pain that occurred earlier (409 +/- 242 vs. 596 +/- 210 s, p < 0.05) and was greater (51 vs. 33 mm, p < 0.05) during the simultaneous infusion of substance P plus adenosine than during infusion of adenosine.”

“We conclude that SP reduction in CSF, which possibly reflects reduced SP turnover after adenosine receptor stimulation, provides an additional possible mechanism of action for the analgesic effects of adenosine.”

“An inactive dose of substance P augmented the morphine-evoked release of adenosine at a nanomolar concentration of morphine.”

“Thus, we suggest that endogenous substance P may potentiate the inhibitory response to endogenous adenosine.”

“Contractions of bronchial muscle evoked by exogenous acetylcholine (2 x 10(-6) M) or substance P (2 x 10(-7) M) were significantly inhibited by the adenosine (3 x 10(-4) M) pretreatment.”

“The results of these investigations demonstrate that adenosine inhibits behavior induced by nociceptive neurotransmitters interacting with spinal substance P or N-methyl-D-aspartate receptors.”