Impact of Duration and Severity of Persistent Pain on Programmed Cell Death

Programmed cell death is a highly regulated form of cell death, mostly distinguished bythe activation of a family of cystein-aspartate proteases (caspases) that cleave various proteinsresulting in morphological and biochemical changes characteristic of this form of cell death.several recent studies have addressed the role of programmed cell death in inflammatory andchronic pain states. caspase-3 plays a central role in mediating nuclear programmed cell deathincluding chromatin condensation and dna fragmentation as well as cell blebbing. the aimsof this study were to investigate the effect of duration and severity of persistent pain on theinduction of programmed cell death. formalin was administered subcutaneously in the wistarrat hind paws for 1,4 or 7 consecutive days, and then the activity ofcaspase-3 was measured inboth the rat liver and brain cells. morphological changes characterizing programmed cell deathwere also studied using the sigma's apoptosis detection kit, annexin v-cy3. our findingsshowed that caspase-3 activity and apoptotic phenotype significantly increased in liver but notbrain cells following the increase in duration and severity of formalin induced persistent pain.