Effects of local anesthesia on gingival cAMP levels

The basal levels of cAMP in the attached gingiva of Rhesus monkeys and the changes in tissue cAMP levels produced by infiltration anesthesia with lidocaine and lidocaine containing 1:100,000 epinephrine were studied. The basal level of cAMP in uninjected monkey gingiva ranged from 12 to 20 picomoles of cAMP per mg of gingival protein. This level was 75 times greater than the cAMP content of monkey blood plasma. Infiltration of the attached gingiva with saline or plain lidocaine for 5 minutes did not produce any significant changes in tissue cAMP levels. Infiltration of the gingiva with lidocaine containing 1:100,000 epinephrine, on the other hand, caused a very marked increase in tissue cAMP levels. Thirty seconds after infiltration with lidocaine with 1:100,000 epinephrine there was a 250% increase in cAMP content of the anesthetized tissue versus the uninjected control tissues. The maximal increase in tissue cAMP levels was observed 5 minutes after infiltration when the cAMP content of the gingiva was 1000 to 1100% above the control level. It is proposed that regulation of tissue cAMP levels by epinephrine or other agents may prove of therapeutic usefulness in regulating inflammation and healing of tissues after surgery or other trauma.