Quantitative Characterization of a Repeated Acute Joint Inflammation Model in Rats

Abstract

1. Chronic pain owing to arthritis is a major clinical problem worldwide. To study the underlying pathological mechanisms of chronic pain and the effectiveness of different treatments, a number of experimental models have been developed over the years. 2. We introduced a new subchronic inflammatory model by repeated unilateral administration of carrageenan into the ankle joint of rats, and investigated the degree and the time-course of the oedema, and thermal and mechanical hyperalgesia. 3. Carrageenan (450 microg) was injected on three occasions (on days 1, 4 and 7), and the resulting oedema, thermal hyperalgesia (paw withdrawal test) and weight load were characterized in voluntarily walking rats daily for 15 days. The effect of diclofenac sodium (3 mg/kg orally daily for 15 days) was also determined. 4. Repetitive administration of carrageenan caused fluctuating oedema and pain responses, which did not normalize within 3 days. Exacerbated inflammatory oedema was observed after the second and third injections. Oedema and a decreased weight load of the inflamed paw were observed throughout the investigation period, and paw withdrawal thresholds to noxious thermal stimuli returned to baseline pre-carrageenan values from Day 13. 5. Oral diclofenac (3 mg/kg daily for 15 days) significantly decreased oedema within a few days (Day 3), whereas its anti-allodynic effect developed only several days later (Day 9). However, diclofenac at the applied dose did not influence the thermal hyperalgesia. 6. The results suggest that the repeated administration of carrageenan might be a suitable model for determining the effects of long-lasting treatment.

Electroporation-enhanced transdermal diclofenac sodium delivery into the knee joint in a rat model of acute arthritis

“…Knee swelling, which is an objective parameter of joint inflammation, was significantly reduced with both the oral and the EP-enhanced diclofenac treatment. 48 Again, this increased volume was significantly reduced by both oral and EP-enhanced diclofenac treatments 48 h after arthritis induction.…”

Evaluation of Laser Phototherapy in the Inflammatory Process of the Rat's TMJ Induced by Carrageenan

“…Carrageenan may induce a highly reproducible local antigenic response and its effects were reported in many studies. 5,18,19,20 A single local injection of 1% carrageenan results in an inflammatory reaction in the TMJ and periarticular tissues, with hyperplasia of the synovial membrane. 7 The dose and dilution of carrageenan used in this study were reported in previous studies that proved its inflammatory effect.…”

“…4 Carrageenan is a polysaccharide widely used for the induction of experimental inflammation on animal models, and it is the most common method for drug testing or assessment of new anti-inflammatory therapies. 5 Some studies have reported the successful utilization of this model to induce both rat paw and joint inflammation. 6,7 Alterations of the synovial membrane have been reported in cases of osteoarthritis of the TMJ.…”

Photobiomodulation versus light-emitting diode (LED) therapy in the treatment of temporomandibular disorder: study protocol for a randomized, controlled clinical trial

“…Both types of phototherapy have been suggested for the treatment of inflammatory joint conditions due to the absence of side effects, which are common with the use of non-steroidal anti-inflammatory drugs (NSAIDs) [ 20 ]. Studies have reported that lasers and LEDs operating with similar parameters produce equivalent effects [ 21 , 22 ]. Different theories have been proposed to explain the analgesic action of phototherapy, but no consensus has been reached.…”