Injury & Pain – Writhing
An intraperitoneal injection of acetic acid or phenylquinone induces a transient state of somatic (visceral) pain. The ability of putative analgesic compounds to block the physiological response is measured.
Morphine (A) and the kappa opioid agonist, U50488 (B), dose-dependently decrease the number of writhes induced by phenylquinone (2.5mg/kg; A) and acetic acid (0.6%; B).
