Quantitative gait analysis as a method to assess mechanical hyperalgesia modulated by disease-modifying antirheumatoid drugs in the adjuvant-induced arthritic rat

In the present study, azothioprine, chloroquine, D-penicillamine, methotrexate and sodium aurothiomalate (gold salt) were evaluated for possible disease-modifying effects in the adjuvant-induced arthritis model of human rheumatoid arthritis in rats. Gait analysis was used to examine the role of disease-modifying antirheumatic drugs in the development of pain. Body weights were also measured to monitor the progression of disease and the systemic antiarthritic effects of the test compounds used in this study, as well as their systemic toxicity. Our results showed that azothioprine (5 mg/kg/day), chloroquine (12.5 mg/kg/day), sodium aurothiomalate (2.5 mg/kg/day) and methotrexate (1 mg/kg/week) not only inhibited the macroscopic changes such as erythema and swelling of limbs, but also exhibited significant reversal of gait deficits seen in the untreated or saline-treated arthritic rats. No reduction in the body weights were observed in the arthritic rats treated with azothioprine, chloroquine, sodium aurothiomalate and methotrexate. D-Penicillamine (12.5 mg/kg/day), however, showed a significant reduction (P < 0.03) in the body weights of the arthritic rats over a period of 22 days; furthermore, it was unable to show any reduction in arthritic score (P < 0.1). In earlier experiments, chloroquine and methotrexate failed to suppress carageenan-induced edema, suggesting that the mode of antiarthritic action may be different from those of nonsteroidal anti-inflammatory agents. Since these disease-modifying antirheumatic drugs are reported to have an immunomodulatory role, especially the gold salt, which influences the monocyte–macrophage system, it is suggested that the observed antiarthritic effects of disease-modifying antirheumatic drugs may be partly attributed to their immunomodulatory activity

Time course of walking speed changes after the induction of arthritis compared with normal rats

<p><b>Copyright information:</b></p><p>Taken from "Quantitative gait analysis as a method to assess mechanical hyperalgesia modulated by disease-modifying antirheumatoid drugs in the adjuvant-induced arthritic rat"</p><p>http://arthritis-research.com/content/9/5/R91</p><p>Arthritis Research & Therapy 2007;9(5):R91-R91.</p><p>Published online 11 Sep 2007</p><p>PMCID:PMC2212551.</p><p></p> Treated arthritic rats or untreated arthritic rats showed a gradual decrease in velocity from day 2 onwards. Arthritic rats treated with azothioprine (AZ), chloroquine (CQ), sodium aurothiomalate (gold salt (GS)), methotrexate (MTX) and indomethacine, however, exhibited a reversal of the deficit in velocity seen in the untreated rats or saline-treated arthritic rats from day 12 onwards. Results are the mean ± standard error (= 6). AC, arthritic control; AIA, adjuvant-induced arthritis; DC, drug control; NT, no treatment; Sal + Art, saline and arthritis

Time course of body weight changes in rats with adjuvant-induced arthritis

<p><b>Copyright information:</b></p><p>Taken from "Quantitative gait analysis as a method to assess mechanical hyperalgesia modulated by disease-modifying antirheumatoid drugs in the adjuvant-induced arthritic rat"</p><p>http://arthritis-research.com/content/9/5/R91</p><p>Arthritis Research & Therapy 2007;9(5):R91-R91.</p><p>Published online 11 Sep 2007</p><p>PMCID:PMC2212551.</p><p></p> Effect of disease-modifying antirheumatic drugs (DMARDs) on the body weight change of the arthritic rats, measured over a period of 22 days. Effect of D-penicillamine (D-PEN) and sodium aurothiomalate (gold salt (GS)) on body weights of adjuvant-induced arthritis (AIA) rats. Effect of azothioprine (AZ), chloroquine (CQ) and methotrexate (MTX) on body weights of AIA rats. Results are the mean ± standard error for six animals per group. AC, arthritic control; DC, drug control; NT, no treatment; Sal + Art, saline and arthritis

Time course of the change in hind paw volume after the induction of arthritis

<p><b>Copyright information:</b></p><p>Taken from "Quantitative gait analysis as a method to assess mechanical hyperalgesia modulated by disease-modifying antirheumatoid drugs in the adjuvant-induced arthritic rat"</p><p>http://arthritis-research.com/content/9/5/R91</p><p>Arthritis Research & Therapy 2007;9(5):R91-R91.</p><p>Published online 11 Sep 2007</p><p>PMCID:PMC2212551.</p><p></p> Rats in all arthritic groups showed an increase in their paw volume until day 8; however, this increase in the azothioprine (AZ)-treated, chloroquine (CQ)-treated and sodium aurothiomalate (gold salt (GS))-treated arthritic rats was not significantly different from the normal control rats, and also no further increase in the paw volume was noticed in these groups. In contrast, arthritic rats treated with methotrexate (MTX) and indomethacine showed a gradual increase in their paw volume over a period of 22 days, but this increase was nonsignificant compared with normal control rats. The arthritic rats treated with D-penicillamine (D-PEN) or saline showed a significant increase in their paw volume over the period of 22 days (< 0.006). Inbox pictures, difference between the arthritic rat paw and the normal rat paw. Results expressed as mean ± standard error (= 6). AC, arthritic control; AIA, adjuvant-induced arthritis; DC, drug control; NT, no treatment; Sal + Art, saline and arthritis

Arthritis severity scores in rats during the development of adjuvant-induced arthritis

<p><b>Copyright information:</b></p><p>Taken from "Quantitative gait analysis as a method to assess mechanical hyperalgesia modulated by disease-modifying antirheumatoid drugs in the adjuvant-induced arthritic rat"</p><p>http://arthritis-research.com/content/9/5/R91</p><p>Arthritis Research & Therapy 2007;9(5):R91-R91.</p><p>Published online 11 Sep 2007</p><p>PMCID:PMC2212551.</p><p></p> Effect of azothioprine (AZ), chloroquine (CQ), D-penicillamine (D-PEN), sodium aurothiomalate (gold salt (GS)) and methotrexate (MTX) on the time course of the development and progression of arthritis, shown as the arthritis severity scores measured over a period of 22 days. Results are the mean ± standard error for six animals in each group. AIA, adjuvant-induced arthritis; DC, drug control; NT, no treatment

Inhibitors of phosphatidylinositide 3-kinase: effects on reactive oxygen species and platelet aggregation

Phosphoinositide 3-kinase (PI 3-kinase) exists in cells as a family of isoforms. The enzymes are important regulators of fundamental metabolic processes, such as energy utilization, growth, cell proliferation and survival. They are activated by cell surface receptors for hormones, and by G-protein coupled receptors. Enzyme p110 gamma, in particular, catalyzes production of second messengers from inositol phospholipids, including phosphoinositide (3,4,5) triphosphate or PtdIns (3,4,5) P3, PtdIns (3,4) P2 and Ptdins (3) P. The objective of this study was to corroborate the role of PI 3 kinase in ROS generation and in platelet aggregation through the use of four chemically unrelated inhibitors of PI 3 kinase: wortmannin, LY-294002, resveratrol and quercetin. In this study, we describe the effects of four PI 3-kinase inhibitors on the production of reactive oxygen species (ROS) and platelet aggregation induced by a diversity of agonists. Neutrophils and platelets were obtained from human blood and macrophages from mouse peritoneal cavity. ROS production was measured by a luminol-enhanced chemiluminescence assay; aggregation was measured in platelet-rich plasma (PRP) with a Chronolog Dual Channel Lumi-Aggregometer. Effects of graded concentrations of four enzyme inhibitors (wortmannin, LY-294002, resveratrol and quercetin) were evaluated. All inhibitors caused concentration-dependent depression of ROS generation and human platelet aggregation. They differed only in their potencies as revealed by concentration-response data. Moreover, inhibitors blocked activity of three chemically unrelated stimulants of aggregation: ADP, collagen and epinephrine. We conclud