icatibant and Arthritis

To investigate the role of proteinase-activated receptor 4 (PAR-4) in mediating joint inflammation and pain in mice.. Knee joint blood flow, edema, and pain sensitivity (as induced by thermal and mechanical stimuli) were assessed in C57BL/6 mice following intraarticular injection of either the selective PAR-4 agonist AYPGKF-NH(2) or the inactive control peptide YAPGKF-NH(2). The mechanism of action of AYPGKF-NH(2) was examined by pretreatment of each mouse with either the PAR-4 antagonist pepducin P4pal-10 or the bradykinin antagonist HOE 140. Finally, the role of PAR-4 in mediating joint inflammation was tested by pretreating mice with acutely inflamed knees with pepducin P4pal-10.. PAR-4 activation caused a long-lasting increase in joint blood flow and edema formation, which was not seen following injection of the control peptide. The PAR-4-activating peptide was also found to be pronociceptive in the joint, where it enhanced sensitivity to a noxious thermal stimulus and caused mechanical allodynia and hyperalgesia. The proinflammatory and pronociceptive effects of AYPGKF-NH(2) could be inhibited by pepducin P4pal-10 and HOE 140. Finally, pepducin P4pal-10 ameliorated the clinical and physiologic signs of acute joint inflammation.. This study demonstrates that local activation of PAR-4 leads to proinflammatory changes in the knee joint that are dependent on the kallikrein-kinin system. We also show for the first time that PARs are involved in the modulation of joint pain, with PAR-4 being pronociceptive in this tissue. Thus, blockade of articular PAR-4 may be a useful means of controlling joint inflammation and pain.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthralgia; Arthritis; Bradykinin; Bradykinin B2 Receptor Antagonists; Disease Models, Animal; Edema; Injections, Intra-Articular; Mice; Mice, Inbred C57BL; Oligopeptides; Receptor, Bradykinin B2; Receptors, Proteinase-Activated; Regional Blood Flow

Tumour necrosis factor-alpha (TNF alpha) was studied in the carrageenin (CG) induced knee-joint incapacitation, and also in mediating recurrent incapacitation response in knee-joints previously exposed to an inflammatory attack. CG or TNF alpha intra-articular injection into CG-primed knee-joints induced an intense and long-lasting (>8 h) peaking incapacitation response. TNF alpha injected in naive joints did not elicit incapacitation. Anti-TNF alpha serum in situ treatment specifically inhibited CG-induced incapacitation in naive joints, and also TNF alpha-induced incapacitation in primed joints. Hoe-140 (D-Arg0[Hyp3,Thi5,D-Tic7,Oic8]-bradykinin, a bradykinin B2 receptor antagonist, given before CG, abolished incapacitation, but was without effect when injected 3 h after. Hoe-140 given before or after the CG injection in primed joints was without effect, but it produced a partial inhibitory effect in the early phase (1 h) of TNF alpha-induced incapacitation. Des-Arg9[Leu3]-bradykinin, a bradykinin B1 receptor antagonist, given intra-articularly after CG or TNF alpha, reversed incapacitation either in naive or primed joints. Indomethacin abolished the incapacitation induced by CG in naive joints, but only the 5-lipoxygenase inhibitor MK-886 plus indomethacin blocked the response in primed joints. MK-886 did not modify CG-induced incapacitation in naive joints, but lately reversed CG-induced incapacitation in primed joints, and blocked TNF alpha-induced response. Substance P or prostaglandin E2 did not induce incapacitation in either naive or primed joints. Our results support the conclusion that TNF alpha is a mediator of CG-induced inflammatory incapacitation, and is able to induce the further release of kinins and leukotrienes, which is suggested to have an important role in the maintenance of long-lasting nociceptive response.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis; Bradykinin; Bradykinin Receptor Antagonists; Carrageenan; Dinoprostone; Inflammation Mediators; Injections, Intra-Articular; Knee Joint; Male; Pain; Rats; Rats, Wistar; Stimulation, Chemical; Substance P; Tumor Necrosis Factor-alpha

The participation of B1 and B2 types of bradykinin receptors was studied in the rat knee-joint incapacitation test. Five intra-articular successive hourly administrations of bradykinin produced progressive incapacitation, thus indicating that bradykinin induced sensitization to its own nociceptive effect. Four co-injections of bradykinin with the bradykinin B1 receptor antagonist des-Arg9-[Leu8]bradykinin were without nociceptive effect. However, a 5th injection of bradykinin alone produced intense incapacitation. The bradykinin B2 receptor antagonist HOE-140 ([D-Arg)[Hyp3,Thi5,D-Tic7,Oic8]bradykinin), or indomethacin, prevented the bradykinin-induced incapacitation. However, successive co-injections of bradykinin with prostaglandin E2, in contrast to bradykinin alone, did induce incapacitation in animals pretreated with indomethacin or HOE-140. The injection of the bradykinin B1 receptor agonist des-Arg9-bradykinin into prostaglandin E2-treated joints did induce incapacitation, although administration of the bradykinin B1 receptor agonist or prostaglandin E2 alone did not induce incapacitation. In conclusion, in ongoing articular inflammation, it is suggested that the bradykinin B1 receptor is particularly involved with nociceptor activation, while the bradykinin B2 receptor is related to nociceptor sensitization.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis; Behavior, Animal; Bradykinin; Bradykinin Receptor Antagonists; Dinoprostone; Hindlimb; Hyperalgesia; Indomethacin; Joints; Male; Nociceptors; Pain Measurement; Rats; Rats, Wistar; Receptors, Bradykinin

To investigate the pathophysiologic roles of endogenous bradykinin (BK) and des-Arg9-BK on local and systemic inflammatory responses in a rat model of acute arthritis induced by peptidoglycan-polysaccharide (PG-APS).. Female Lewis rats were injected intraperitoneally with PG-APS. Selective antagonists of B1 (Lys-[Leu8]-des-Arg9-BK) and B2 (Hoe 140) receptors were infused at 500 microg/kg and 5 mg/kg per day for 6 days, starting 3 days before induction of inflammation, with subcutaneous micro-osmotic pumps. The local inflammatory response was assessed by paw edema, joint swelling, and tissue content of BK and des-Arg9-BK. These peptides were measured by highly sensitive and specific chemiluminescent enzyme immunoassays. Systemic inflammatory reaction was evaluated by the hepatic concentration of the type 2 acute-phase protein T-kininogen.. PG-APS induced significant paw edema and joint swelling 24-72 hours after intraperitoneal injection. The maximal responses to PG-APS observed at 72 hours were significantly reduced (31-38%) by the combination of both B1 and B2 receptor antagonists at 5 mg/kg per day. PG-APS induced a significant increase of BK (up to 5.3-fold) and des-Arg9-BK (up to 4.1-fold) 72 hours after challenge. Liver T-kininogen content was increased by 5.3-, 7.7-, and 5.8-fold at 24, 48, and 72 hours, respectively, after PG-APS injection. At 24 hours, Hoe 140 and Lys-[Leu8]-des-Arg9-BK increased liver T-kininogen content by 43% and 45%, respectively, but they had no effect at 72 hours.. The results indicate that endogenous kinins are involved in local and systemic acute inflammatory responses, through both B1 and B2 kinin receptors, in the model of PG-APS-induced arthritis.

Topics: Acute Disease; Animals; Arthritis; Bradykinin; Bradykinin Receptor Antagonists; Disease Models, Animal; Female; Kininogens; Liver; Peptidoglycan; Rats; Rats, Inbred Lew

Methods have been optimised for the collection of synovial fluid and the chromatographic separation of individual kinins (bradykinin and kallidin) in the fluid by HPLC. In addition, the stability of the kinin antagonist, Hoe 140, in synovial fluid was compared with that of synthetic bradykinin. Although bradykinin was completely degraded after incubation for only 6 h in pooled synovial fluid obtained from patients with rheumatoid arthritis, Hoe 140 was stable for as long as 2 weeks under the same conditions. These studies will provide quantitative information regarding levels of kinins in inflamed joints and an insight into the therapeutic potential of kinin antagonists.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Arthritis; Bradykinin; Chromatography, High Pressure Liquid; Drug Stability; Humans; In Vitro Techniques; Kinins; Recombinant Proteins; Synovial Fluid