Substance IP Potentiates the A 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 . Background. Substance P is involved in the generation of neurogenic inflammation and causes cutaneous hyperalgesia . Because substance P is present in perivascular nerves it might also cause muscular and cardiac hyperalgesia. To test this hypothesis its effects on adenosine-induced muscular and cardiac pain were Investigated in humans . Methods. A randomized, crossover study of the algogenic effects of the intraillac infusion of increasing scalar doses (from 125 to Q* pg%0 of adenosine or substance P (1L2 pmollmin) for 3 min, followed by the simultaneous infusion of substance P plus the same doses of adenosine, was carried out in nine patients with no evidence of peripheral vascular disease . A similar protocol was carried out by infusing increasing scalar doses of adenosine (from 50 to 800 lag/min) or substance P (11 .2 pmol/min) for 3 min, followed by the simultaneous infusion of substance P plus the same doses of adenosine, into the left coronary artery of eight patients