Influence of prednisolone and L-thyroxine on the changes in collagen metabolism in rats with adjuvant-induced arthritis

In rats with adjuvant-induced arthritis the effects of prednisolone and L-thyroxine on the changes in collagen metabolism were investigated both in the skin and tendon during the acute and chronic phase of the arthritis. In untreated animals with adjuvant-induced arthritis, a decrease in the collagen synthesis accompanied by an increase in the catabolism of collagen and a retardation in the conversion of soluble to insoluble collagen were noted both in the skin and tendon during the course of the disease. Prednisolone was found to accelerate the conversion of soluble to insoluble collagen and to inhibit the enhanced catabolism of collagen in rats with adjuvant-induced arthritis. L-Thyroxine accelerated the conversion of soluble to insoluble collagen in adjuvant-induced arthritic rats more effectively than prednisolone but was less effective with regard to the inhibition of enhanced catabolism of collagen. However, the synthesis of collagen in adjuvant-induced arthritis was improved by both prednisolone and L-thyroxine.     

Influence of dipyridamole and its combination with NO donor or NO synthase inhibitor on adjuvant arthritis

The anti-arthritic and anti-inflammatory effects of dipyridamole and the possible involvement of NO in the dipyridamole action are not yet clear. The aim of this study was to evaluate the effects of dipyridamole alone and in combination with either the nitric oxide donor, sodium nitroprusside (SNP) or the non-selective nitric oxide synthase inhibitor, L-NG- monomethyl arginine (L-NMMA), on pathogenesis of adjuvant-induced arthritis model in rats. The results of the present work showed that prophylactic administration of dipyridamole alone and dipyridamole administration in combination with either low dose of SNP or L-NMMA significantly ameliorated pathogenesis of adjuvant arthritis in rats as evidenced by significant decrease in arthritis index, hind paws volume, loss of body weight, hyperalgesia compared with control vehicle (1% DMSO) treated adjuvant arthritic rats. Inflammatory cellular infiltrate in synovium of ankle joint and pannus formation were also markedly inhibited. Interleukin-10(IL-10) levels were significantly increased in these groups of animals. In contrast, a high dose of SNP counteracted the anti-inflammatory and anti-arthritic effects of dipyridamole. The inhibitory effect of therapeutic administration of dipyridamole alone on adjuvant arthritis syndrome was not significantly different from that of vehicle administration. In conclusion, dipyridamole has prophylactic but not therapeutic anti-arthritic and anti-inflammatory effects that appear to be dependent on inhibition of NO synthase. A synergistic combination between dipyridamole and NO synthase inhibitor or low dose of NO donor may have prophylactic and therapeutic values in autoimmune diseases like RA.     

Dual effect of nitric oxide donor on adjuvant arthritis

The effect of medical use of NO donors on the pathogenesis of arthritis is still yet unclear. We investigated the effects of the NO donor, sodium nitroprusside (SNP), on the pathogenesis of adjuvant-induced arthritis in rats. Rats were given SNP intraperitoneally either from day 5 to day 14 (as a prophylactic protocol) or from day 16 to day 25 (as a therapeutic protocol) after inoculation of adjuvant. SNP administration, whether prophylactic or therapeutic, in doses of 0.1 and 1 mg/kg/d significantly aggravated pathogenesis of adjuvant arthritis in rats. SNP-treated rats showed significant (P < 0.05) increase in arthritis index, hind paw volume, ankle joint diameter and hyperalgesia compared with control adjuvant arthritic rats. However, in adjuvant rats given the smallest dose of SNP (0.01 mg/kg/d), arthritis index, volume of hind paws, ankle joint diameter, body weight loss, and hyperalgesia were significantly lower than that of control adjuvant rats. After 30 d of the induction of adjuvant arthritis, TNF alpha levels exhibited insignificant changes either in control adjuvant rats or in rats given SNP compared with control non adjuvant rats. IL-10 levels in adjuvant control rats and adjuvant rats given 1 mg or 0.1 mg/kg/d from day 15 to day 25 were significantly lower than that of control non adjuvant rats. Histopathology examination of ankle joint showed that large doses of SNP (1 mg or 0.1 mg/kg/d) increased the mononuclear cells infiltration and erosion of cartilage induced by adjuvant while the infiltration of the inflammatory cells in the synovium of adjuvant rats treated with 0.01 mg/kg/d was minimal and the pannus was inhibited with alleviation of erosion of articular cartilage. Prophylactic small dose of SNP improved the histological status more than the therapeutic small dose. The present work reveals that SNP administration, either prophylactic or therapeutic, was deleterious in higher doses. However, the smallest dose used 0.01 mg/kg/d attenuates joint inflammation, hyperalgesia and body weight loss in adjuvant arthritic rats. These results suggest that small dose of NO donor may exert partial protective effects while the safety of the clinical use of NO donors, in higher doses, in patients with rheumatoid arthritis is questioned.     

Clinical safety of flurbiprofen

Data from 58 premarketing studies of the nonsteroidal antiinflammatory drug flurbiprofen were pooled for analyses of adverse drug reactions (ADRs). These studies included 5602 patients treated with flurbiprofen (N = 4123), aspirin (N = 1033), or placebo (N = 446) for varying durations. Diagnoses included rheumatoid arthritis, osteoarthritis, and other painful musculoskeletal conditions. In these studies serious upper gastrointestinal ADRs occurred in flurbiprofen-treated patients at less than one half the rate seen in aspirin-treated patients. The incidence of serious urinary tract ADRs was lower with flurbiprofen than with aspirin. The flurbiprofen group had no serious clinical ADRs related to the hemic/lymphatic system. The most common laboratory abnormality was a decrease in hematocrit, which occurred less often than in the aspirin group. We also evaluated serious flurbiprofen-related ADRs in 4370 patients in a variety of other studies and reviewed published reports of flurbiprofen clinical trials and case reports. These reviews showed no additional, unanticipated patterns of intolerance. These clinical safety data indicate that in the doses studied, flurbiprofen is a well tolerated agent for patients requiring nonsteroidal antiinflammatory drug therapy.     

Influence of the intestinal microflora on the elimination of warfarin in the rat

The effect of the intestinal microflora on the half-life and elimination of warfarin in rats was examined. When the intestinal microflora was reduced with neomycin, bacitracin, and tetracycline, or was nonexistent as in germ-free animals, more radioactivity was found in feces and less in the urine after ip administration of 14C-warfarin. The ratio of conjugated to free metabolites in the feces was higher in germ-free rats compared to conventional or ex-germ-free animals. In addition, fecal beta-glucuronidase levels were markedly decreased in antibiotic-treated rats and in germ-free rats when compared to conventional and ex-germ-free rats. In a crossover study, a 30% decrease in warfarin half-life was observed in germ-free and antibiotic-treated animals compared to the same rats in an ex-germ-free state. The antibiotic treatment, however, had effects other than reduction of the microflora. A significant decrease in the volume of distribution of warfarin was noted in antibiotic-treated animals which may invalidate the use of this widely used mixture as a model for the study of intestinal microflora-drug interactions. To confirm enterohepatic recycling of warfarin, bile from donor rats administered 14C-warfarin ip was infused into the upper duodenum of recipient rats. Bile from the recipient rats was shown to contain 0.1-0.9% of the radioactivity administered to the donor rats. At 6-8 hr after injection, serum of the recipient rats contained 2-10% of the radioactivity present in the serum from donor rats, and contained mainly free warfarin. These data are consistent with an important role for the intestinal microflora in facilitating enterohepatic recycling of warfarin in the rat.     

Prevention of galactosamine-induced hepatotoxicity in rats with fructose-1,6-diphosphate.

Galactosamine (GalN) administration produces hepatitis-like liver injury in animals. The hepatotoxicity of GalN is attenuated by several interventions, including activation of the reticuloendothelial system (RES). Fructose-1,6-diphosphate (FDP) administration significantly increases the phagocytic activity of the RES in animals. Thus, investigations were designed to determine whether FDP affords protection against GalN toxicity. Rats were injected with GalN (375 mg/kg) and treated with 0.9% NaCl (n = 8) or FDP (n = 9). Eight rats were sham-operated. Serum glutamic oxaloacetic transaminase was 40 times higher in the saline group as compared to the FDP-treated rats (p less than 0.0001). Glutamic pyruvic transaminase, gamma-glutamyltranspeptidase and bilirubin were similarly elevated (saline vs. FDP, p less than 0.005, p less than 0.01 and p less than 0.05, respectively). These values were not different between FDP-treated and sham-operated rats. Extensive hepatic necrosis was observed in all saline-treated rats, whereas in the FDP group only isolated foci of hepatocellular necrosis were noted. The hepatoprotective effect of FDP in this model is attributed to its ability to enhance the phagocytic activity of RES and to suppress release of oxyradicals by the leukocytes during the inflammatory phase.     

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.     

Eicosanoid production and phospholipase A2 secretion by peritoneal macrophages from rats with adjuvant-induced arthritis.

The effect of adjuvant-induced arthritis on rat peritoneal macrophage (RPM) function with respect to [14C]arachidonic acid (AA) release, leukotriene B4 (LTB4) and prostaglandin E2 (PGE2) production, and secreted phospholipase A2 (PLA2) activity was investigated. Twice as many cells were lavaged from the peritoneal cavity of arthritic rats 21 days post-adjuvant injection than were lavaged from normal rats. PGE2 production was increased two-fold in Ca++ ionophore-stimulated RPM from the adjuvant animals as compared with RPM from control animals. However, PLA2 secretion, LTB4 production and [14C]AA release were unchanged. These results suggest that PGE2 production, rather than LTB4 production or PLA2 secretion, is preferentially enhanced in Ca++ ionophore-stimulated RPM from arthritic rats and may, therefore, reflect a major role for PGE2 in adjuvant-induced arthritis. However, the presence of increase numbers of macrophages and their associated products, including PLA2 and LTB4, may also contribute to the inflammatory process in this disease.     

Enantioselective kinetic disposition of fenoprofen in rats with experimental diabetes or adjuvant-induced arthritis

This study was aimed to investigate the influence of diabetes or arthritis on the enantioselective metabolism and kinetic disposition of fenoprofen in rats with streptozotocin-induced diabetes or Mycobacteriumtuberculosis adjuvant-induced arthritis. Animals received i.v. 10 mg/kg racemic fenoprofen and blood samples were collected up to 24 h thereafter, with 5 animals studied at each time point. Plasma concentrations of the fenoprofen enantiomers were determined by HPLC. Diabetic and arthritic animals showed significant differences when compared with respective controls for the following pharmacokinetic variables of the (+)-(S)-fenoprofen eutomer: area under the plasma concentration time curve, total clearance and volume of distribution. The results indicate that experimental diabetes and adjuvant-induced arthritis influence the fenoprofen enantioselective metabolism.     

木瓜丸对大鼠佐剂性关节炎的防治作用

目的：探讨木瓜丸对大鼠佐剂性关节炎的预防及治疗作用。方法：建立大鼠佐剂性关节炎模型，观察不同阶段给药对佐剂性关节炎的影响。结果：木瓜丸预防性给药，能抑制注射局部炎症和8d后的再肿胀，抑制对侧后肢因迟发性超敏反应引起的足肿胀；对继发病变的预防性给药，可抑制对侧足肿胀，使注射侧足肿胀明显消退，减轻再肿胀的程度；对继发病变的治疗性给药，可降低注射对侧足爪的肿胀度、前肢和尾部的病变度。结论：木瓜丸对大鼠佐剂性关节炎的原发病变和继发病变有显著的预防和治疗作用。     

Adjuvant polyarthritis. VIII. Differences in immunopathogenesis between type II collagen arthritis and adjuvant arthritis

The severity of type II collagen-induced arthritis was found to correlate with the serum titers of anti-type II collagen antibody, but not with cell-mediated immunity to type II collagen. In contrast, no significant levels of either the humoral or the cell-mediated immunity to type II collagen were found in rats with Freund's complete adjuvant-induced arthritis. Pre-treatment of young rats with an oily preparation of type II collagen prevented the development of arthritis in these animals in response to a subsequent injection of oily preparation of type II collagen, but had no effect on the development of arthritis in response to a subsequent injection of Freund's complete adjuvant. It is concluded that while an immune response directed toward the injected type II collagen is responsible for the development of type II collagen arthritis, it does not play an important role in the induction of Freund's adjuvant-induced arthritis.     

Effect of honeybee (Apis mellifera) venom on the course of adjuvant-induced arthritis and depression of drug metabolism in the rat

The ability of honeybee venom to suppress Mycobacterium butyricum-induced arthritis was studied in Lewis rats. Bee venom, 2 mg.kg-1.day-1 for 24 days, suppressed but did not abolish the primary and secondary inflammatory responses to the adjuvant as monitored by decreases in the swelling of the left and right hind paws and adjuvant-induced arthritis on heme metabolism were also examined. Bee venom or adjuvant had no effect on hepatic delta-aminolevulinic acid synthase, porphyrin content, or ferrochelatase activity. However, with both treatments cytochrome P-450 and the associated enzymic activities of ethylmorphine N-demethylase and benzo[a]pyrene hydroxylase were depressed markedly. In contrast, both treatments caused several-fold enhancement of hepatic microsomal heme oxygenase activity. Adjuvant-treated rats receiving bee venom showed changes in heme metabolism which were of a magnitude similar to those observed when either agent was administered to the experimental animals. Although the bee venom appears to suppress adjuvant-induced arthritis to a greater extent in female than in male rats, the alterations in heme metabolism were similar in bee venom-treated male and female rats. The observed changes in heme metabolism elicited by the venom or by the adjuvant are strongly suggestive of perturbations of the immune system causing alterations in hepatic microsomal enzymes.     

The effect of immunomodulating drugs on adjuvant-induced arthritis in Lewis rats

The purpose of this study was to investigate the effects of cyclosporine A (CSA) and methotrexate (MTX) as potential immunomodulators in a nonestablished adjuvant arthritis (AA) model. Non-injected hind paw volumes were reduced when AA rats were treated for 18 days with CSA (100% at 10 mg/kg) or MTX (100% at 0.1 mg/kg). Body weights of drug treated AA rats were increased above untreated AA rats and were similar to non-arthritic controls. AA rats show elevated T helper (W3/25+)/T suppressor (OX 8+) cell ratios (2.0 vs. 3.1, p less than 0.01). The immunomodulators tested all returned these elevated ratios to control non-arthritic levels. Similarly, these drugs returned the reduced mitogen responses and elevated blood granulocyte numbers toward normal non-arthritic control values.     

Humoral and cellular immunologic aspects of adjuvant and collagen arthritis in rats

Systemic and local immunological responses of rats sensitized with either M. butyricum or native type II collagen have been evaluated. In rats exhibiting adjuvant-induced arthritis no antibodies to collagen could be detected. In animals exhibiting collagen-induced arthritis, high antibody titers developed by day 14, and could be correlated with the severity of the arthritis. Delayed type hypersensitivity (DTH) responses were measured by a 5-iodo-2'-deoxyuridine 125-I (125-IUdR) uptake assay. Arthritic scores in rats immunized with collagen were not accompanied by a positive DTH response, whereas adjuvant arthritic rats showed a positive response. T-lymphocyte cellular responses in both adjuvant- and collagen-induced arthritic rats were measured. In neither syndrome were major alterations observed in T-lymphocyte subpopulations. These results provide evidence that adjuvant-induced arthritis and type II collagen-induced arthritis are distinct entities, and that they may be discriminated by the nature of the humoral response.     

甲氨喋呤对佐剂性关节炎大鼠滑膜髓样分化因子MyD88表达的影响

目的探讨甲氨蝶呤对佐剂性关节炎大鼠滑膜组织中髓样分化因子(myeloid differentiation primary response protein,MyD88)的表达的影响及抑制滑膜炎症的可能机制。方法清洁级SD大鼠30只,随机分为正常组(10只)和完全弗氏佐剂造造模组(20只),造模成功后随机分成2组,模型组和甲氨蝶呤组,每组10只。分别干预4周后,取膝关节滑膜,HE染色观察大鼠滑膜病理改变,免疫组化观察MyD88在滑膜中的定位,Western Blot法检大鼠滑膜中MyD88的表达,EILISA法检测炎性因子IL-1β的表达。结果模型组大鼠膝关节滑膜组织病理改变明显且炎性因子IL-1β的表达较正常组明显升高(P0.001),而经甲氨蝶呤治疗后,大鼠滑膜组织病理改变减轻、炎性因子IL-1β的表达降低(P0.001)。模型组大鼠关节滑膜中MyD88表达升高,与正常组相比具有统计学意义(P0.001),经甲氨蝶呤治疗后MyD88的表达降低,与模型组比较有统计学意义(P0.05)。结论佐剂性关节炎大鼠滑膜中MyD88的表达明显升高,而甲氨蝶呤可以抑制MyD88的表达从而降低关节滑膜炎症因子IL-1β的表达,改善滑膜增生及炎性因子浸润等病理进程。     

Suppression of adjuvant arthritis of rats by a novel matrix metalloproteinase-inhibitor

BAY 12-9566 (4-[4-(chlorophenyl)phenyl]-4-oxo-2S-(phenylthiomethyl) butanoic acid) is a newly developed, synthetic matrix metalloproteinase (MMP) inhibitor (MMPI) that selectively inhibits MMP-2, MMP-3 and MMP-9 isozymes. We study the effect of BAY 12-9566 on inflammation and cartilage destruction in adjuvant-induced arthritis (AA) in rats. Rats were injected with adjuvant and treated for 21 days with vehicle, Indomethacin or BAY 12-9566. AA was assessed: by measuring arthritic index, paw volume, urinary pyridinoline (Pyr) and deoxypyridinoline (Dpyr); by examining joint inflammation; and by microscopic morphometry of articular cartilages. Oral treatment of rats for 22 days with 50 mg kg(-1) body weight/d BAY 12-9566 showed decreased AA as determined by improvement in body weight gain (P<0.01), arthritic index (P<0.05) and swelling of paws contralateral to the adjuvant injection site (P<0.05). Neutrophil infiltration and collagen degradation were also significantly lower (P<0.01) in this treatment group. Cartilage destruction was successfully suppressed (P<0.01) in rats treated with either 50 mg kg(-1) body weight/d BAY 12-9566 or 1 mg kg(-1) body weight/d Indomethacin. These results indicate that BAY 12-9566 successfully suppressed inflammation and cartilage destruction in rats with AA. Moreover, these results also suggested that MMP-2, MMP-3 and MMP-9 are involved in arthritic diseases such as rheumatoid arthritis.     

Development of the rabbit model for studying the effects of propranolol on cardiac contractility: relationship of intravenous pharmacodynamics and pharmacokinetics

The New Zealand white rabbit (3-4 kg) was chosen as an experimental model to determine the effects of propranolol, by intravenous bolus administration, on cardiac contractility. The cardiovascular effects were measured by systolic time interval recordings for up to 8 h. The study was performed on two groups of animals with 5 rabbits receiving active drug and another 5 rabbits receiving saline placebo. All animals were anesthetized by parenteral administration of urethane/acepromazine. The results indicated that at 15 min after intravenous administration, propranolol caused a maximum decrease in heart rate (p less than 0.01), as well as a maximum increase in QS2 (p less than 0.01), LVET (p less than 0.01), PEP (p less than 0.01) and PEP/LVET (p less than 0.05). Approximately 90 min after drug administration, a significant (p less than 0.01) "rebound phenomenon" was observed in the active group which continued throughout the 8-h observation period. This preliminary study suggests that the rabbit is a useful animal model to study the effects of propranolol on cardiac contractility.     

Impaired intrinsic chiral inversion activity of ibuprofen in rats with adjuvant-induced arthritis

1. The effects of adjuvant-induced arthritis on the chiral inversion of 'profens', a type of non-steroidal anti-inflammatory drug, have hardly been investigated. The authors investigated the effects of adjuvant-induced arthritis on the chiral inversion of ibuprofen using freshly isolated rat hepatocytes. 2. S- or R-ibuprofen was incubated with hepatocytes isolated from control and adjuvant-induced arthritis rats in the absence of the serum. In the hepatocyte system the chiral inversion rate constant of R- to S-ibuprofen and the metabolic rate constants of both enantiomers in adjuvant-induced arthritis rats were significantly decreased to about 64-80% of the corresponding values in control rats. In contrast, the addition of serum from each group to the corresponding hepatocyte medium resulted in no significant differences in these rate constants between control and adjuvant-induced arthritis rats. 3. With regard to chiral inversion enzymes, adjuvant-induced arthritis decreased the messenger RNA levels of acyl-coenzyme A synthetase (ACS) isoforms, but not 2-arylpropionyl-CoA epimerase, compared with control rats. 4. Chiral inversion of R- to S-ibuprofen was inhibited by triacsin C, a specific inhibitor of ACS1. 5. The results suggest that adjuvant-induced arthritis induces down-regulation of ACS enzymes involved in chiral inversion of R- to S-ibuprofen in rats.     

Steroid-sparing action of flurbiprofen: use of an additional parameter of joint scans with 99m technetium.

A double-blind placebo controlled trial was carried out in 14 steroid-dependent patients with rheumatoid arthritis to assess the effectiveness and steroid-sparing action of flurbiprofen over a 4-week period. During the first week, the patients' steroid dosage was stabilized at the minimum necessary to control symptoms. They were then treated with either 100 mg flurbiprofen or placebo 3-times daily for 3 weeks. Steroid dosage was initially reduced to 50% of the stabilized dose and reduced further if practicable, depending on therapeutic response. Clinical assessments were made, at weekly intervals, of pain, swelling, tenderness, erythema, range of movement, grip strength, walking time, and duration of morning stiffness. Joint scanning of 99mTc uptake was also measured before and after treatment in 11 patients. The results showed that whereas 3 out of 6 patients on placebo has distinct inflammatory flare-up, this did not occur in any of the 8 patients on flurbiprofen. Moreover, 3 of the flurbiprofen group showed improvement and a further reduction in steriod dosage was possible in 3 patients. Improvements in joint scans correlated well with the clinical findings in 6 of 11 patients.     

Glucuronidation Kinetics of R,S-Ketoprofen in Adjuvant-Induced Arthritic Rats

Purpose. A pharmacokinetic study was carried out in rats to investigate the effect of arthritis on the glucuronidation of the nonsteroidal anti-inflammatory drug ketoprofen. Methods. An iv bolus dose of R,S-ketoprofen (10 mg/kg) was administered to control (n = 6) and adjuvant-induced arthritic rats (n = 6). All experiments were carried out in bile-exteriorized animals. Concentrations of R- and S-ketoprofen in plasma, bile and urine, and of their glucuronides in bile and urine were determined by HPLC. In a separate series of experiments, the ex vivo plasma protein binding of R- and S-ketoprofen was measured in control and arthritic rats following iv administration of R,S-ketoprofen. Results. As a result of a significant decrease in plasma albumin concentrations in arthritic rats, the unbound fraction of R- and S-ketoprofen was significantly increased (approximately 2-fold) in rats with adjuvant-induced arthritis. Total (i.e., bound plus unbound) plasma clearances of R- and S-ketoprofen were not different in arthritic rats. Unbound plasma clearances of both ketoprofen enantiomers, however, were significantly reduced (by 53% and 61%, respectively). This was due to a significant impairment in the formation of the R- and S-ketoprofen glucuronides. There was no apparent effect of adjuvant-induced arthritis on the chiral inversion of R- to S-ketoprofen. Conclusions. Adjuvant-induced arthritis in the rat leads to a significant impairment in the in vivo glucuronidation of R- and S-ketoprofen.