Observations on the algogenic actions of adenosine compounds on the human blister base preparation

Abstract

The action of the adenyl compounds ATP, ADP, AMP and adenosine was studied on the human blister base preparation. All 4 adenyl compounds produced pain which was slow in onset and not maintained. The threshold concentration for pain was of the order of 1-3 .mu.M. The slopes of log concentration:pain intensity plots were relatively shallow, and for moderate to severe pain a 100-fold increase of the threshold concentration was required. The adenyl compounds resembled 5-hydroxytryptamine and bradykinin with respect to onset and duration of action, but were less potent. For threshold effects they were more potent than acetylcholine or K+. Evidence was found for an interaction of adenyl compounds with 5-hydroxytryptamine, but not with K+, acetylcholine or bradykinin. Cyclic AMP or the chelation of extracellular Ca2+ or Mg2+ were not involved in the algogenic action of adenyl compounds, and the action of adenyl compounds on the rabbit isolated jejunum was also unrelated to their algogenic action on the human blister base preparation.