Inflammatory pain


Porsolt offers models of acute and chronic pain and inflammation matching the needs of the industry and maintaining a recognized expertise, which addresses pain therapeutic endpoints and pain associated symptoms and side effects.

Inflammatory pain

Formalin test: late phase in the mouse (licking score)

Mice are given an intraplantar injection of formalin into one hind paw which induces paw licking in control animals. Mice are briefly observed at 1 minute intervals for 35 minutes after the injection of formalin and the number of occasions that the mice are observed licking the injected paw is recorded.

Complete Freund's Adjuvant (CFA) - induced chronic inflammatory pain: monoarthritis model in the rat

Rats are injected with a suspension of Freund's adjuvant into the tibio-tarsal joint. Evaluation of analgesic/anti-inflammatory test substance are proposed either acutely 7 or 14 days after CFA administration or after 7 or 14-day repeated administration.
For the clinical symptoms, a paw use/gait score is recorded after observing the rats in an open arena. Inflammation is measured by evaluation of swelling of the affected joint. For the pain symptoms, each paw is evaluated by the occurrence of vocalizations following 5 consecutive flexions-extensions.

MIA-induced chronic inflammatory pain: osteoarthritis model in the rat

Monosodium iodoacetate (MIA) is injected through the infra-patellar ligament into the joint space of one knee.

On testing day, all animals are evaluated for inflammation as well as clinical symptoms and their pain response is evaluated following 5 consecutive flexions-extension, tactile and thermal stimulations of both hindpaws.

In both models several pain measures can be used
> Tactile stimulation (tactile allodynia or tactile hyperalgesia): measured using an electronic von Frey apparatus or a pinchmeter.
> Thermal stimulation (heat hyperalgesia): measured using the Hargreaves method.

In addition edema is measured using plethysmometer