Carrageenan-induced oedema in the rat paw - histamine participation

Participation of histamine in the inflammatory reaction produced by carrageenan was studied. Mepyramine did not influence the course of the inflammatory reaction. In contrast to when mepyramine was used, there was a significant inhibition of carrageenan oedema when cimetidine was used. Pretreatment of animals with compound 48/80 significantly reduced the oedema formation. Neither mepyramine nor cimetidine reversed the inhibition of rat paw swelling produced by histamine liberators. It is concluded that histamine participates in carrageenan oedema via its H2-receptors and that the anti-inflammatory effect of compound 48/80 is not connected with the 'anti-inflammatory' action of liberated histamine.     

The release of leukotriene B4 during experimental inflammation

Leukotriene B4 (LTB4) has been detected by radioimmunoassay in inflammatory exudates obtained following the implantation of saline- or carrageenan-soaked polyester sponges in rats. The immunoreactive material was confirmed as LTB4 after extraction and purification by high pressure liquid chromatography. The peak concentration (6.9 +/- 0.5 ng/ml) was detected 6 hr after implantation of sponges soaked in 0.5% carrageenan; thereafter the level declined and was undetectable after 16-24 hr. The concentration of LTB4 during the early phase of the inflammatory response (4-8 hr) is sufficient to induce leukocyte aggregation, chemotaxis and degranulation of polymorphonuclear leukocytes (PMN) in vitro. Therefore, LTB4 may mediate, at least in part, the influx of PMN and contribute to other events which characterise the inflammatory response. The level of thromboxane B2 (TXB2) in the inflammatory exudate followed a similar time-course to that of LTB4 although the maximum concentration was higher (15-30 ng/ml). However, prostaglandin E2 (PGE2) exhibited a different time-course; the maximum level (20-30 ng/ml) was also reached 6-8 hr after implantation but remained elevated at 24 hr. The PMN count in the sponges and the concentrations of both LTB4 and TXB2, but not PGE2, were significantly reduced by prior treatment of the animals with colchicine. This suggests that PMN are the major source of LTB4 and TXB2 in the inflammatory exudate whereas PGE2 is produced in significant amounts by other tissues.     

Relevance of tumour necrosis factor-alpha for the inflammatory and nociceptive responses evoked by carrageenan in the mouse paw

1. The present study evaluated the participation of tumour necrosis factor-alpha (TNF-alpha) in the inflammatory and nociceptive responses evoked by carrageenan in the mouse paw. 2. The intraplantar injection of carrageenan (300 microg paw-1) induced a marked and biphasic paw oedema formation (peaks at 6 and 72 h), which was accompanied by a long-lasting mechanical allodynia (that remained elevated for up to 72 h) and a significant increase of myeloperoxidase (MPO) activity (peak at 6 h) in both Swiss and C57/BL6 mice. 3. The paw oedema, the elevation of MPO activity and to a lesser extent the mechanical allodynia elicited by carrageenan were found to be significantly reduced in TNF-alpha p55 receptor knockout mice. 4. Of interest, the systemic administration of an anti-TNF-alpha antibody produced a significant inhibition of paw oedema, mechanical allodynia and MPO activity. A noteworthy decrease in inflammatory and nociceptive responses caused by carrageenan was also observed when mice were previously treated with the preferential inhibitor of TNF-alpha synthesis, thalidomide. 5. The present results clearly indicate that the proinflammatory cytokine TNF-alpha plays a critical role in the oedema formation, as well as in the mechanical allodynia and the neutrophil migration, following carrageenan administration into the mouse paw. Intraplantar injection of carrageenan in mice could constitute a useful model for assessment of the in vivo effects of potential inhibitors of TNF-alpha-related pathways.     

The effect of ABT-702, a novel adenosine kinase inhibitor, on the responses of spinal neurones following carrageenan inflammation and peripheral nerve injury

1. Adenosine (ADO) receptor activation modulates sensory transmission in the dorsal horn. Little is known about the circumstances underlying release of the purine. The present study was conducted to investigate the effect of a novel and potent non-nucleoside adenosine kinase (AK) inhibitor, ABT-702, on the responses of dorsal horn neurones to selected peripheral stimuli. ABT-702 is orally effective to reduce behavioural signs of nociception in models of acute, inflammatory, and neuropathic pain. 2. Electrophysiological recordings were made from wide dynamic range (WDR) neurones in halothane-anaesthetized rats. ABT-702 was given subcutaneously following either carrageenan inflammation or peripheral nerve injury (L5/L6 spinal nerve ligation). Comparisons were made between carrageenan and uninjected control animals, and similarly between spinal nerve ligated (SNL) and sham operated animals. 3. ABT-702 produced inhibition of the postdischarge, wind-up and C-fibre evoked responses in both carrageenan and nerve-injured animals. Furthermore, the mechanical and thermal evoked responses were similarly reduced in SNL rats. Overall, ABT-702 produced a significantly greater inhibition of these responses in SNL rats as compared to sham controls. Similarly ABT-702 tended to produce greater effects after carrageenan inflammation, however this did not reach significance. 4. Protection of endogenous adenosine by ABT-702 therefore produces a marked inhibition of the noxious evoked neuronal activity in inflamed and neuropathic rats. Our results demonstrate a plasticity in the endogenous adenosine-mediated inhibitory system following SNL and provide a possible basis for the use of this compound for the treatment of neuropathic and other persistent pain states.     

On the ability of prostaglandin E1, and arachidonic acid to modulate experimentally induced oedema in the rat paw.

1 Prostaglandins E1 and E2 but not prostaglandin F2alpha, arachidonic acid or linolenic acid, produced slight oedema when injected into the rat hindpaw. 2 Prostaglandin E1 potentiated hindpaw oedema produced by carrageenan, kaolin, bradykinin and trypsin but not that produced by 5-hydroxytryptamine (5-HT), histamine, dextran B or compound 48/80. Carrageenan- and bradykinin-induced paw oedemas were also potentiated by prostaglandin E2. Arachidonic acid potentiated responses to carrageenan and kaolin but not responses to bradykinin, trypsin, 5-HT, histamine, dextran B or compound 48/80. Linolenic acid did not potentiate hindpaw oedema induced by carrageenan. 3 Potentiation of carrageenan-induced oedema by prostaglandin E1 was not diminished by pretreatment with indomethacin, hydrocortisone or cyproheptadine. However, arachidonic acid potentiation of carrageenan oedema was reduced by pretreatment with non-steroidal anti-inflammatory drugs but not by anti-inflammatory steroids or by paracetamol. 4 The enhancement of the response to carrageenan and kaolin by prostaglandins E1, E2 and arachidonic acid is discussed in terms of kinin mediation.     

Evidence for bradykinin mediation of carrageenin-induced inflammatory pain: a study using kininogen-deficient Brown Norway Katholiek rats

Inflammatory pain was induced following an intradermal injection of carrageenin into rat paws, and the hyperalgesia was measured in terms of withdrawal time following thermal pain stimulation of the inflamed paw. This hyperalgesia was significantly less in kininogen-deficient Brown Norway (B/N)-Katholiek rats, which also showed less swelling in carrageenin-induced paw edema, than in normal B/N-Kitasato rats at 1 approximately 4 hr after the carrageenin injection (at the early phase). However, 24 hr after the injection, hyperalgesia and the swelling volume of the kininogen-deficient rats were almost the same as those in normal rats. The bradykinin B2 receptor antagonist FR173657, (E)-3-(6-acetamido-3-pyridyl)-N-[N-[2,4-dichloro-3-[(2-methyl-8-quinolinyl)oxymethyl]phenyl]-N-methylaminocarbonylmethyl]acrylamide, attenuated the carrageenin-induced swelling and hyperalgesia of the normal rats at the early phase to almost the levels of the B/N-Katholiek rats. Pretreatment with indomethacin, a cyclooxygenase inhibitor, also inhibited the carrageenin-induced responses significantly in normal rats. These results indicate that bradykinin, acting on the B2 receptor, is the main mediator at the early phase of inflammatory pain of carrageenin edema and that prostaglandins, produced by cyclooxygenase, potentiate the effects of bradykinin.     

Aggravation of adjuvant arthritis by carrageenan

• 1.1. We have studied the optimum conditions for the induction of adjuvant carrageenan-induced inflammation (ACII) in male Wistar rats with limited susceptibility to adjuvant arthritis (AA).
• 2.2. ACII was induced by intradermal injection of Freund's complete adjuvant (CFA), containing 10 mg/ml Mycobacterium tuberculosis, followed by a subplantar inoculation of the nonspecific inflammatory stimulus carrageenan at different times.
• 3.3. Data obtained indicate that the arthritis of rats inoculated with CFA is significantly increased by carrageenan, particularly when it is injected 14 days after the adjuvant. Arthritis enhancement was more evident in the joints of the leg that had been previously injected with carrageenan, and remained stable around the peak level for some weeks. The development of joint inflammation was associated histologically with the appearance of inflammatory cells in the synovial membrane of those animals.
• 4.4. We found that the injection of carrageenan aggravated the course of AA in general, but very significantly when administered at the moment of the appearance of arthritis (day + 14). This aggravation affected both the intensity of inflammation and the chronicity of the disease.

     

Different patterns of spinal cyclooxygenase-1 and cyclooxygenase-2 mRNA expression in inflammatory and postoperative pain

Levels of cyclooxygenase-2 (COX-2) mRNA, but not those of COX-1, were reported to be raised significantly after peripheral inflammation in the rat spinal cord. The aim of the present study was to ascertain whether this pattern of COX-2 and COX-1 expression applies also to other pain conditions induced by surgical procedure. Experiments were performed on two types of pain models. In a model of postoperative pain, 1 cm longitudinal incision was made through skin, fascia and muscle of the plantar aspect of the right hind paw in anaesthetized rats. In the second model, peripheral inflammation was induced by unilateral, intraplantar injection of carrageenan in the right hind paw. Carrageenan injection or skin incision produced marked and significant reduction of paw withdrawal latencies to noxious radiant heat stimuli after 2 and 6 hr. Under the acute inflammation 2 and 6 hr after carrageenan injection levels of COX-2 mRNA were markedly raised (7.8 and 15.5 times; P<0.001, respectively) while spinal levels of COX-1 mRNA were not significantly altered (n.s.). In contrast, spinal levels of COX-2 mRNA were raised less markedly in a model of postoperative pain (4.9 times at 2 hr; P<0.001 and 2.9 times (n.s.) at 6 hr after surgery) whilst levels of COX-1 mRNA in the lumbar spine were increased significantly (2.3 times; P<0.001) 6 hr after surgery. The present findings indicate that expression of COX-2 mRNA in the spine is less dominant in postoperative pain than in inflammatory pain and that spinal COX-1 mRNA is upregulated in postoperative pain.     

Effect of pre-existing inflammation on carrageenan-induced paw oedema in rats

Twenty-four hours after injection of carrageenan into one hind paw, injection of the same amount into the contralateral paw produced a significantly attenuated inflammatory response. However, when the second injection was given 7 days later, the inflammation induced in the contralateral paw was comparable with the initial response to carrageenan. A time-course study of carrageenan-induced inflammation in rats showed that significant oedema persisted 24 h after carrageenan administration and complete recovery was achieved in 7 days. The attenuated inflammatory response in the contralateral paw after 24 h was antagonized by bilateral adrenalectomy and chemical sympathectomy induced by 6-hydroxydopamine. Carrageenan-induced paw oedema was also significantly less in rats with subacute inflammation induced by the croton oil granuloma pouch technique. This attenuated response was antagonized by pretreatment of the rats with metyrapone, an inhibitor of adrenocorticoid synthesis, and by 6-hydroxydopamine. It is likely that the pre-existing acute or subacute inflammation attenuates the inflammatory response of carrageenan, by acting as a stressor, inducing activation of the sympatho-adrenal system.     

Effect of exposure to radiation on the inflammatory process and its influence by diclofenac.

The effect of radiation exposure on the inflammatory process was studied in rats using the carrageenan-induced paw oedema and adjuvant-induced arthritis tests. Irradiation (0.5,1 and 2 Grays) resulted in a significant augmentation of the tissue response to carrageenan and the early phase of adjuvant-induced arthritis, but suppressed the late phase. Diclofenac (1-5 mg kg-1) effectively reduced the exaggerated inflammatory response in irradiated animals in both the carrageenan paw oedema and adjuvant-induced arthritis tests. The drug also had a prophylactic value in guarding against the induction of radiation damage. The inflammatory responses produced by irradiation and the benefits obtained by drug treatment may be related to changes in tissue prostaglandin levels and/or changes in the immune system.     

Modulatory effect of fosfomycin on acute inflammation in the rat air pouch model

We examined the effect of fosfomycin (FOM) on the inflammatory response induced by carrageenan in the rat. Air pouches were induced subcutaneously on the backs of rats and injected with carrageenan. The rats were treated with either vehicle or FOM at a dose of 100 mg/kg 1 h before carrageenan challenge. After carrageenan challenge (48 h), the air pouches were removed and analyzed. The volume, protein amounts and cell counts in the exudate obtained from FOM-treated animals were significantly reduced compared with that from vehicle-treated animals. The contents of PGE(2) and TNF-alpha, and mRNA for cyclooxygenase-2 were also markedly suppressed in FOM-treated rats. Histological examination showed suppression of the inflammatory response in the pouch tissues from FOM-treated rats.     

Negative endocrine control system for inflammation in rats

Inflammatory processes may be suppressed by endogenous mechanisms such as release of adrenocorticosteroid hormones through stimulation of the hypothalamus-pituitary-adrenal axis. In the present study, the relationship between the temporal development of carrageenan-induced edema in the hindlimb of the rat and release in plasma of the principal endogenous adrenocorticosteroid of the rat corticosterone was investigated. Suplantar injection of carrageenan produced a biphasic increase in basal plasma corticosterone levels that was not attributed to diurnal variation. The plasma level of corticosterone increased rapidly after injection of carrageenan and peaked 12-fold at 20 min. This first phase increase was attributed to the stress of the injection since it was mimicked by subplantar injection of saline. The second phase of corticosterone release was gradual and peaked 12-fold 7 hr after injection of carrageenan. The second phase was not elicited by subplantar injection of saline. When the hypothalamus-pituitary-adrenal axis is impaired via hypophysectomy, carrageenan-induced edema is more intense and lasts longer than in control rats. The results demonstrate that adrenocorticosteroid hormones are released as a result of the stress of injection and by the inflammatory response. Release of adrenocorticosteroids acts as a feedback mechanism to suppress the inflammatory response.     

Simvastatin and Indomethacin Have Similar Anti‐Inflammatory Activity in a Rat Model of Acute Local Inflammation

Abstract: Statins, such as simvastatin, lower circulating cholesterol levels and are widely prescribed for the treatment of hypercholesterolaemia. Several studies have shown unexpected effects of statins on inflammation. We studied the anti‐inflammatory effect of simvastatin using a standard model of an acute local inflammation, the carrageenan‐induced footpad oedema. Experimental groups (n = 6–8) were given simvastatin in a dose range 5–30 mg/kg, indomethacin 1–8 mg/kg and methylcellulose (control) per os. Footpad volume was measured with a plethysmograph and compared with the pre‐injection volume of the same paw. Swelling (in microlitres) was then calculated, and in drug‐treated animals, per cent inhibition was derived through comparison with the control group. Histopathological examination of the skin biopsies was performed to examine severity of paw skin lesions and to confirm the simvastatin‐induced inhibition of acute inflammation. Both simvastatin and indomethacin administered orally, 1 hr before carrageenan injection, significantly reduced the extent of footpad oedema. Indomethacin dose‐dependently blocked the swelling; the maximal effect was obtained with 8 mg/kg by 48.3% (P < 0.05). Simvastatin produced a comparable anti‐inflammatory activity at a dose of 5 mg/kg (32%), while 10 and 30 mg/kg caused a 47.6% and 51.7% reduction, respectively, with the maximal effect observed at 20 mg/kg by 57.2% (P < 0.05). The comparison of the ED₅₀ of these agents on molar basis showed equipotent anti‐inflammatory activity. Histopathological examination of the footpad skin biopsies revealed that simvastatin, dose‐dependently and comparablly to indomethacin, reduced polymorphonuclear leucocyte infiltration. These data support the hypothesis that simvastatin has an acute anti‐inflammatory activity.     

一清胶囊抗炎作用实验研究

目的研究一清胶囊的抗炎作用,为其临床应用提供科学依据。方法采用二甲苯诱导小鼠耳肿胀、角叉菜胶诱导大鼠足肿胀,评价其抗炎作用。结果一清胶囊高(29.3g·kg~(-1))、低(3.7g·kg~(-1))剂量组均可显著减轻二甲苯致小鼠耳肿胀(P<0.05);高(11.7g·kg~(-1))、中(5.9g·kg~(-1))、低(2.9g·kg~(-1))剂量组均可显著抑制角叉菜胶致大鼠足肿胀(P<0.01),其作用在致炎后1和3h表现明显,且高剂量组在致炎后6h内的作用强于醋酸泼尼松组。结论一清胶囊具有较好的抗炎作用。     

Anti-inflammatory synergy of MEN16132, a kinin B2 receptor antagonist, and dexamethasone in carrageenan-induced knee joint arthritis in rats

BACKGROUND AND PURPOSE

Bradykinin, through its B₂ receptor, is involved in inflammatory processes related to arthropathies. In carrageenan and lipopolysaccharide (LPS)-induced arthritis in rat, the anti-inflammatory activity of MEN16132, a potent and selective kinin B₂ receptor antagonist, was compared with that of steroidal and nonsteroidal anti-inflammatory drugs. The interaction between MEN16132 and dexamethasone was also investigated.

EXPERIMENTAL APPROACH

Drugs, alone or in combination, were injected into the knee joint 30 min before intra-articular administration of carrageenan or LPS, in pentobarbital anaesthetized rats. Effects on incapacitation, oedema, neutrophil recruitment and kallikrein system activation, in the knee joint, were assessed.

KEY RESULTS

MEN16132 and dexamethasone (10–300 µg per knee) dose-dependently reduced carrageenan-induced joint pain, oedema and neutrophil infiltration, reaching a maximal inhibition of about 50%. Dexketoprofen exerted a similar analgesic activity, whereas it did not affect the other inflammatory responses. MEN16132 showed a partial inhibition of LPS-induced joint pain, whereas dexamethasone produced a full analgesic effect. Combination of MEN16132 and dexamethasone showed a strong synergistic interaction in inhibiting both carrageenan and LPS-induced knee joint inflammation. Dexamethasone did not prevent the contact activation of prekallikrein by carrageenan and the subsequent release of kallikreins and bradykinin in the synovium.

CONCLUSIONS AND IMPLICATIONS

Steroids and kinin B₂ receptor antagonists appear to relieve arthritic symptoms induced by carrageenan or LPS and act synergistically to inhibit joint inflammation. This could have interesting therapeutic implications, possibly opening the way for combination therapies in the control of inflammatory arthropathies.     

Inhibition of carrageenan-induced paw edema by superoxide dismutase that binds to heparan sulfates on vascular endothelial cells

The effect of heparin-binding superoxide dismutase (HB-SOD), a fusion gene product consisting of human Cu/Zn-SOD and a C-terminal basic domain with high affinity for heparin-like proteoglycans, was examined on carrageenan-induced paw edema in mice and rats. When injected intravenously to mice just before carrageenan, HB-SOD suppressed significantly paw edema. ED30 of HB-SOD (1000 units/kg) was markedly lower than that of SOD (bovine free Cu/Zn-SOD, 7000 units/kg). When HB-SOD was administered with heparin (500-2000 units/kg), edema was suppressed more markedly than by HB-SOD alone. In contrast, the suppressive action of SOD was decreased by heparin. HB-SOD also suppressed carrageenan paw edema in rats with an ED30 of 2500 units/kg which was also obtained by SOD. Heparin prolonged significantly the duration of HB-SOD suppression of edema. The inhibitory effect of HB-SOD alone disappeared within 5 hr of injection, while more than 80% of the effect remained at this time when HB-SOD has been injected with 1000 units/kg of heparin. Heparin failed to enhance the anti-inflammatory effect of SOD under any of the conditions tested and heparin alone showed no suppression up to 5 hr after injection. HB-SOD might permit studies on pathophysiological events in and around vascular endothelial cells where reactive oxygen species play critical roles.     

Prostaglandins and the anti-inflammatory activities of aspirin and sodium salicylate.

Acetylsalicylic acid (aspirin) and sodium salicylate are equally effective in reducing the swelling in the carrageenan-induced paw test and the accumulation of leucocytes into the inflammatory exudate produced by the subcutaneous implantation of polyvinyl sponges in the rat. Aspirin but not sodium salicylate caused a significant reduction in the potentiation of paw oedema found after the concurrent administration of carrageenan and arachidonic acid. Some implications of these findings are discussed.     

Effects of central and peripheral depletion of serotonergic system on carrageenan-induced paw oedema

The role of serotonergic system was investigated on peripheral inflammation induced by intraplantary injection of carrageenan. Para-chlorophenylalanine (PCPA) was administered intracerebroventriculary (50, 100 microg/rat) or intraperitoneally (150 mg/kg, 3 days) and 2 or 24 h later, respectively, inflammation was induced by injection of carrageenan. Paw oedema was decreased significantly in PCPA-treated (100 microg/rat, i.c.v.) rats compared to control groups. Injection of exogenous serotonin (i.c.v.) by dose of 0.70 nmol/10 microl/rat, but not the dose of 0.35 nmol/10 microl/rat, 15 min after induction of inflammation completely reversed the anti-inflammatory effects of PCPA. Myeloperoxidase activity in inflamed paws was reduced significantly in groups received PCPA (either i.c.v. or i.p.) compared to controls. Exogenous serotonin (0.70 nmol/10 microl/rat) reduced inflammatory response when injected (i.c.v.) 30 min before or 30 min after the induction of inflammation. Injection of serotonin at the time of induction of inflammation had no inflammatory/anti-inflammatory effect. These results suggest that serotonin, as a neurotransmitter in central nervous system, may be involved in modulating peripheral inflammation.