Effect of μ-opioids morphine and buprenorphine on the development of adjuvant arthritis in rats

Objective and Design: On the basis that endogenous opioids play a role in the physiological response to inflammation, this study tests the antiarthritic effects of a μ-opioid agonist, morphine and the partial μ-agonist, buprenorphine. Material: Male Lewis rats were used. Treatment: Rats were innoculated subcutaneously with 0.05 ml of Freund's complete adjuvant (5 mg/ml) into the right hind paw to produce adjuvant arthritis. Morphine (either 10 to 60 mg/kg/day s.c. bolus or 60 mg/kg/day s.c. infusion) and buprenorphine (0.65±0.06 mg/kg/day, orally), respectively, were administered for 3 days during the primary inflammatory phase of adjuvant arthritis. Methods: The progression of adjuvant arthritis was monitored every three days by body weight change and hind limb oedema (ipsilateral and contralateral). On day 21 the animals were sacrificed and histology and radiography of the contralateral limb were performed. In rats receiving Freund's adjuvant and no drug treatment, the incidence of arthritis was 89%. Effect was expressed as the pooled severity index (PSI) derived from the arithmetic average of the volume, histology and radiography scores in the contralateral hind limb. Results: Buprenorphine had no effect on experimental arthritis (PSI control vs treated: 242±28 vs 253±28%). In contrast, morphine by subcutaneous injection twice daily (10 to 60 mg/kg/day) but not by subcutaneous infusion (60 mg/kg/day) was found to attenuate the progression of adjuvant arthritis in a dose-dependent manner. This indicates that the anti-arthritic effects of morphine are opioid receptor mediated (ED₅₀, 58±9 mg/kg) and suggests that the local concentration reached effective levels only after subcutaneous injection. It is also possible that the high doses of morphine were anti-inflammatory through effects at the kappa receptor. However, these high doses of morphine produced death in one third of the rats, the calculated lethal dose (LD₅₀, 63±2 mg/kg) being close to the effective dose. Conclusion: Anti-arthritic effects of morphine are opioid receptor mediated but morphine use for this indication is restricted by its adverse effects. accepted by M. J. Parnham     

索拉非尼对大鼠佐剂性关节炎的抑制作用

目的探讨索拉非尼对大鼠佐剂性关节炎(AA)的抑制作用。方法 36只雄性SD大鼠均分为6组,除正常组外,其余各组大鼠均制备AA模型。足容积法检测AA大鼠继发侧足爪容积;流式细胞术检测外周血CD4~+及CD8~+T细胞亚群的变化;免疫组织化学链霉卵白素-过氧化物酶法(SP)检测滑膜组织微血管密度(MVD)的改变。结果与模型组相比,索拉非尼组大鼠足爪容积下降,滑膜组织MVD减小,其中索拉非尼(20、40mg/kg)组可使外周血CD4~+T细胞比例降低,CD8~+T细胞比例增加,差异均有统计学意义(P0.05)。结论索拉非尼具有抑制大鼠AA效应,该作用可能与索拉非尼引起AA大鼠外周血CD4~+,CD8~+T细胞亚群的偏移以及降低滑膜组织MVD有关。     

Inhibitory effect of allopurinol on adjuvant arthritis in rats

The effect of Allopurinol (ALLO), on adjuvant arthritis was studied in rats and compared with the effect of indomethacin (IND). Drugs were given by intraperitoneal injection for each day beginning from the day of adjuvant injection (day 0) and continued until the 16th day. Paw swelling was measured on days 4, 17 and 29, and secondary lesions were assessed on days 17 and 29. Polymorphonuclear leukocyte (PMNs) count was also evaluated on day 17.ALLO, at relatively high doses (25–50 mg/kg), reduced paw swelling of the adjuvant-injected extremity on day 4; lower doses (6.25–12.5 mg/kg), however, elicited the same inhibitory effect on day 17. IND (0.25 mg/kg) also prevented paw swelling on days 4 and 17. Both ALLO and IND reduced the secondary lesions on days 17 and 29 and prevented the increase in polymorphonuclear leukocytes during the development of adjuvant arthritis. Possible mechanisms of the antiinflammatory effect of ALLO in adjuvant arthritis are discussed.     

Taurine chloramine modifies adjuvant arthritis in rats

Inflammation Research - .     

Manipulation of the induction of adjuvant arthritis in Sprague-Dawley rats

Objective To investigate the roles of various variables in the induction of adjuvant-induced arthritis (AIA) in the outbred Sprague-Dawley (SD) rats, and further characterize its arthritic features by comprehensive examinations. Methods The roles of different preparative techniques, inoculation routes and doses of Mycobacterium tuberculosis (MT) suspension as well as the sex preference in the induction of AIA were comparatively studied using clinical assessment. The hind paws of animals were analyzed by radiological and histological examinations. The serum levels of cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were determined by ELISA. Results The particle size and dose of MT played a dominant role in the induction and severity of AIA. Male rats manifested markedly more severe arthritic signs than female rats. After subcutaneously inoculated with 500 μg MT, male rats developed pronounced arthritis with 100% incidence and low variable clinical signs. Even using only 62.5 μg MT, AIA was efficiently induced in male rats and characterized by upregulated expression profiles of IL-1β, IL-6 and TNF-α. Conclusions Since outbred SD rats are much cheaper and more readily available than Lewis rats, this well-developed SD rat AIA model is an efficient and cost-effective arthritis model available for screening novel anti-arthritic agents. Received 13 February 2006; returned for revision 23 March 2006; accepted by J. Di Battista 31 March 2006     

Studies of the effect of mitoxantrone on adjuvant induced arthritis in rats

When rats with developing or established adjuvant arthritis are treated with mitoxantrone, the hind paw inflammation associated with the disease is inhibited. Radiographic analysis of the hind paws indicates that the agent suppresses joint destruction associated with the lesion. Comparative studies with cyclophosphamide indicate that mitoxantrone is more efficacious and at least 20 times more potent than cyclophosphamide. Mitoxantrone also appeared more effective when given by the subcutaneous route than the peritoneal route of administration.     

Pavlovian conditioning of immunosuppression modifies adjuvant arthritis in rats

Ten days prior to induction of adjuvant arthritis (by injection of complete Freund's adjuvant into a rat's hind paw), three groups of rats were dosed with cyclophosphamide (CY), an immunosuppressive drug. A saccharin/vanilla solution (SV) was presented either 2 days (Group NC) or immediately before CY treatment (Groups C and C2). Three further SV presentations started either 30 min (Groups C and NC) or 2 days after antigenic stimulation (Group C2). The groups did not differ with respect to the degree of swelling in the injected paws. In contrast, Group C differed significantly from Groups NC and C2 with respect to the uninjected hind paws: Group C showed no external signs of a proliferation of inflammation, whereas approximately half of the animals in the other two groups developed small lesions. A second experiment, similar to the first, yielded the same results. These results essentially confirm previous findings on conditioned immunosuppression and extend them to an inflammatory joint disease.     

The effect of adjuvant arthritis on the subsequent local inflammatory response in rats

An assessment was made of the cellular inflammatory response to the subcutaneous implantation of sterile nitrocellulose discs and polyvinyl sponges in both normal rats and rats with adjuvant-induced arthritis. It was found that from 3 days after adjuvant injection the treated animals exhibited a reduced accumulation of inflammatory cells onto the nitrocellulose discs and that this impairment in response was not apparent until the discs had been retained for longer than 24 h. When discs were implanted after non-arthritogenic doses of adjuvant constituents or injection of brewer's yeast no effect was seen on the subsequent response. When polyvinyl sponges were used in adjuvant-treated animals a similar initial reduction in cellular accumulation was observed, which was later followed by increased cell numbers associated with enhanced granuloma formation. Differential cell counts revealed that both neutrophil and mononuclear cell types were affected. Some of the possible mechanisms involved in these observations are discussed.     

佐剂性关节炎大鼠免疫功能的实验研究

目的：阐明佐剂性关节炎（ＡＡ）大鼠模型免疫病理特征及发病机理。方法：应用费氏完全佐剂诱发大鼠产生裸关节佐剂性关节炎,研究其免疫功能变化。结果：ＡＡ大鼠致敏侧及时对侧后肢裸关节均发生明显炎性肿胀,其脾细胞对ＳＲＢＣ诱导的抗体生成反应明显增强,但其脾细胞对ＰＷＭ诱导的ＩｇＣ的产生及血清类风湿因子（ＲＦ）水平与对照组相比并无升高。ＡＡ大鼠对ＣｏｎＡ诱导的脾细胞增殖反应较对照组显著降低,脾细胞抑制活性降低     

Acetylsalicylic acid and misoprostol combination in adjuvant arthritis of rats

The combined effect of acetylsalicylic acid (ASA) and misoprostol (MISO) on adjuvant arthritis was investigated on rats. Alteration by various doses of MISO and fixed dose of ASA was studied. Drugs were given by the nasogastric route each day beginning from the day of adjuvant injection (day 0) and continued until the 16th day. Paw swelling was measured on days 4, 17, and 29, and secondary lesions were assessed on days 17 and 29. Pathological examination of tibiodorsal junction was also evaluated on the 29th day. The results clearly showed that the combination of MISO with ASA did not inhibit the antiinflammatory effect of ASA. Unexpectedly, MISO increased the antiinflammatory effect of ASA at some dosage regimens.     

The effect of adjuvant arthritis on the subsequent local inflammatory response in rats.

An assessment was made of the cellular inflammatory response to the subcutaneous implantation of sterile nitrocellulose discs and polyvinyl sponges in both normal rats and rats with adjuvant-induced arthritis. It was found that from 3 days after adjuvant injection the treated animals exhibited a reduced accumulation of inflammatory cells onto the nitrocellulose discs and that this impairment in response was not apparent until the discs had been retained for longer than 24 h. When discs were implanted after non-arthritogenic doses of adjuvant constituents or injection of brewer''s yeast no effect was seen on the subsequent response. When polyvinyl sponges were used in adjuvant-treated animals a similar initial reduction in cellular accumulation was observed, which was later followed by increased cell numbers associated with enhanced granuloma formation. Differential cell counts revealed that both neutrophil and mononuclear cell types were affected. Some of the possible mechanisms involved in these observations are discussed.     

鬼针草总黄酮对大鼠佐剂性关节炎的治疗作用及机制

目的 探讨鬼针草总黄酮(TFB)对大鼠佐剂性关节炎(AA)关节肿胀指数、炎症因子水平、toll样受体4（TLR4）信号转导通路及病理评分的影响。方法 选取50只雄性SD大鼠,随机分为空白组、模型组、TFB(40 mg/kg、80 mg/kg、160 mg/kg)组,每组各10只。比较各组大鼠关节肿胀指数;采用放射免疫法检测血清白细胞介素1β（IL-1β）、肿瘤坏死因子α（TNF-α）的水平;Western blotting检测巨噬细胞中TLR4、核因子κB（NF-κB）的表达水平;HE染色进行大鼠关节病理评分。结果 模型组关节肿胀指数、炎症因子水平、TLR4及NF-κB表达均明显高于空白组,不同剂量的TFB组（40 mg/kg、80 mg/kg、160 mg/kg）关节肿胀指数、炎症因子水平、TLR4、NF-κB表达及病理评分均显著低于模型组(P<0.05),且TFB剂量越大,所有指标表达水平越低(P<0.05)。结论 TFB对AA大鼠具有治疗作用,其作用机制可能与降低关节肿胀指数及炎症因子水平、抑制TLR4和NF-κB表达、阻碍血管翳形成有关。     

Preventive actions of a high dose of glucosamine on adjuvant arthritis in rats

Objective: Glucosamine, a naturally occurring amino monosaccharide has been used to treat or prevent osteoarthritis in humans. In this study, we evaluated the effect of glucosamine on rat adjuvant arthritis, a model of rheumatoid arthritis.Materials and methods: Adjuvant arthritis was induced in male Wistar rats by injection of Freunds complete adjuvant (FCA) into the right hind paw, and 300 mg/kg of glucosamine, an extra-dose compared with a regular dose for osteoarthritis patients (1.5 g/day, approximately 25 mg/kg), was orally administered once a day to the arthritic rats for 22 days.Results: Glucosamine significantly suppressed the increase in arthritis score (p < 0.05) after day 10 of adjuvant injection, and inhibited the swelling of FCA-injected right and -uninjected left hind paws (p < 0.01) after day 18. In addition, histopathological examination of the arthritic joints revealed that glucosamine suppressed synovial hyperplasia, cartilage destruction and inflammatory cell infiltration. Furthermore, glucosamine reduced the production of nitric oxide and prostaglandin E₂ in plasma (p < 0.05).Conclusions: These observations suggest that glucosamine is able to suppress the progression of adjuvant arthritis in rats. Glucosamine may be expected as a novel anti-inflammatory agent for treatment of rheumatoid arthritis.Received 4 July 2004; returned for revision 8 October 2004; accepted by M. Katori 10 November 2004     

Effect of nutritional copper deficiency on adjuvant arthritis and immunocompetence in the rat

Both severe and marginal copper deficiency were produced in male Sprague Dawley rats prior to induction of adjuvant arthritis. Degree of copper deficiency was confirmed by analysis of plasma, liver, and brain samples prior to adjuvant injection. Incidence of adjuvant arthritis was the same in both copper deficient and control animals although the severity was slightly but not statistically less in the former. However, recovery from foot edema was impaired in copper-deficient animals, while marginally copper-deficient animals recovered at the same rate as did controls. Plasma copper concentration increase in response to the injection of adjuvant and the increase was directly related to dietary copper content. Plasma zinc concentration was decreased in arthritic animals and the decrease was inversely correlated to paw edema. Liver copper, zinc, and iron concentrations in arthritic animals remained unchanged or increased slightly in comparison to the corresponding non-injected controls. Copper-deficient rats were immunosuppressed as demonstrated by impaired responsiveness to the T-cell dependent contact sesitizing agent oxazolone and diminshed capacity to respond to the T-cell independent antigen Type III pneumococcal polysaccharide. Although a statistical difference in paw volumes was not found for group of animals fed diets differing in copper content, it is postulated that copper deficiency may alter the severity and kinetics of adjuvant arthritis by impairing aspects of the immune response and the tissue repair processes subsequent to injury.     

清络通痹颗粒对佐剂性关节炎大鼠炎症细胞因子的影响

目的观察清络通痹颗粒对佐剂性关节炎大鼠细胞因子含量的影响.方法采用弗氏完全佐剂性制备大鼠佐剂性关节炎模型,观察清络通痹颗粒对佐剂性关节炎大鼠IL-1、TNF-α的影响.结果清络通痹颗粒[7.2,14.4 g/(kg*d).ig]能明显降低佐剂性关节炎大鼠IL-1、TNF-α水平.结论清络通痹颗粒具有抑制佐剂性关节炎大鼠细胞因子异常产生的作用.     

Effect of lactoferrin on the development of acute and chronic adjuvant arthritis

An experiment revealed that the therapeutic administration of lactoferrin exerted no effect on the development of early stages of adjuvant arthritis in albino rats during chronicity. This was accompanied by decreased complement consumption and by the lower blood activity of polymorphonuclear leukocytes. The authors consider that this effect is associated with the capacity of lactoferrin to inhibit the excessive proinflammatory activity of neutrophilic leukocytes, which is characteristic of the chronicity of inflammation.     

Immunoglobulins from rats that are resistant to adjuvant arthritis suppress the disease in arthritis-susceptible rats

The therapeutic effect of high doses of polyclonal immunoglobulins has been well established in various B cell-associated autoimmune diseases. In the present work we have examined the effect of low doses of immunoglobulins in adjuvant arthritis, a T cell-associated disease in the Lewis rat. Lewis rats were treated with purified rat immunoglobulins as well as their Fc and F(ab′)₂ fragments and their protective effect on adjuvant arthritis was evaluated. We found that early as well as late treatment with low doses of rat immunoglobulins induced refractoriness to disease induction. The effect was found to be carried out by the F(ab′)₂ part of the immunoglobulins and could be adsorbed by affinity purification on Mycobacterium tuberculosis. The protective antibodies were present in Fisher and BN rats that are resistant to adjuvant arthritis, but not in the arthritis susceptible Lewis and Wistar strains. We suggest that resistance to autoimmune arthritis is associated with the presence of protective immunoglobulins and that their effect is carried out through the antigen recognition part of the molecule.