Lumiracoxib,a highly selective COX-2 inhibitor

Lumiracoxib (Prexige^®, Novartis AG) is a highly selective inhibitor of cyclooxygenase-2 that has been approved in 22 countries including the UK for analgesic therapy in chronic and acute pain. For patients with osteoarthritis, the recommended initial dose is 100 or 200 mg once daily, in one or two divided doses. In patients with primary dysmenorrhea, or following dental or orthopedic surgery with moderate-to-severe acute pain, the recommended dose is 400 mg once daily. The Therapeutic Arthritis Research and Gastrointestinal Event Trial (TARGET) tested the efficacy and gastrointestinal safety of the drug against two traditional nonselective nonsteroidal anti-inflammatory drugs, naproxen and ibuprofen. The results from this trial demonstrated that lumiracoxib reduces gastrointestinal ulcer complication rates by 66% overall and 79% among nonaspirin users in a population without gastroprotection. Lumiracoxib was not associated with a statistically significant difference in cardiovascular morbidity and mortality compared with nonselective nonsteroidal anti-inflammatory drugs. However, in view of the ongoing debate about the safety of cyclooxygenase-2 inhibitors, the use of this drug class should be limited to patients with increased risk of gastrointestinal complications until results of randomized trials in cardiovascular high-risk populations are published.     

COX-2/sEH双抑制剂PTUPB抑制肝星型细胞活化减轻小鼠肝纤维化

目的 探讨花生四烯酸（ARA）经细胞色素P450(CYPs)及环氧合酶2(COX-2)代谢途径在非酒精性脂肪肝（NAFLD）相关肝纤维化中的作用,并从肝星形细胞（HSC）活化的角度探讨其机制。方法采用雄性C57BL/6J小鼠为研究对象,高糖高脂饲养（HFD）诱导小鼠NAFLD相关肝纤维化模型。给予小鼠每天皮下注射COX-2/可溶性环氧化物水解酶（sEH）双抑制剂PTUPB(5 mg/kg)。12周后观察COX-2/sEH双抑制对小鼠NAFLD相关肝纤维化的影响。记录小鼠体重变化;检测小鼠葡萄糖耐受性;HE染色观察小鼠肝组织病理损伤;油红O染色观察小鼠肝组织脂质堆积;Masson染色及Western blot法检测肝组织胶原含量;Real-time PCR法检测小鼠肝组织基质金属蛋白酶抑制因子相关基因表达;Western blot法检测PTUPB对棕榈酸（PA）诱导的肝星形细胞JS1活化的影响。结果 PTUPB可显著降低HFD小鼠的体重,提高小鼠葡萄糖耐受性,减轻肝组织病理损伤、脂质堆积和胶原沉积;PTUPB亦可降低HFD小鼠肝组织基质金属蛋白酶抑制因子Timp1及Timp2的基因表达;...     

Distribution of constitutive (COX-1) and inducible (COX-2) cyclooxygenase in postviral human liver cirrhosis: a possible role for COX-2 in the pathogenesis of liver cirrhosis

AIMS: Prostaglandins produced by the action of cyclooxygenases (COX) are important mediators of systemic vasodilatation and inflammation in liver cirrhosis. The aim of this study was to investigate the distribution of COX-1 and COX-2 in postviral cirrhosis. METHODS: The immunohistochemical expression of the constitutive (COX-1) and the inducible (COX-2) isoenzymes was investigated in 15 patients with cirrhosis after hepatitis B and C infection; three normal control livers were also analysed. RESULTS: COX-2 was absent from normal liver but was highly expressed in cirrhosis, mainly in the inflammatory, sinusoidal, vascular endothelial, and biliary epithelial cells. Low amounts of COX-1 were expressed in both normal and cirrhotic livers, exclusively in sinusoidal and vascular endothelial cells, with no differences seen between normal and cirrhotic livers. CONCLUSIONS: COX-2 is overexpressed in liver cirrhosis, and possibly contributes to prostaglandin overproduction, which may be a major component of the inflammation and hyperdynamic circulation associated with cirrhosis. Because COX-2 is thought to contribute to tumour development, high COX-2 production could be a contributor to hepatocellular carcinoma development in cirrhosis. The finding of COX-2 and not COX-1 upregulation in cirrhosis could provide a possible new role for selective COX-2 inhibitors in reducing inflammation and minimising the occurrence of hepatocellular carcinoma in patients with cirrhosis.     

Effect of the selective COX-2 inhibitors, celecoxib and rofecoxib in rat acute models of inflammation

OBJECTIVE: This study evaluates the action of celecoxib and rofecoxib, two selective cyclooxygenase-2 (COX-2) inhibitors in two acute models of inflammation, carrageenan (Cg)-induced rat pleurisy, and paw oedema formation. MATERIAL: Male Wistar rats (N = 4-10 per group) were used. A fixed volume of PBS or carrageenan was injected into the pleural cavity or into the paw. Furthermore, the myeloperoxidase (MPO) activity and the levels of nitrite/nitrate (NOx), interleukin-1beta (IL-1beta), tumor necrosis factor-a (TNF-a) and PGE2 were also assessed in the paw tissue or in pleural exudate. RESULTS: Dexamethasone (DEX, 0.5 mg kg(-1), s.c., -4 h) and indomethacin (INDO, 3 mg kg(-1), p.o., -1 h) suppressed Cg-induced pleural exudate accumulation by 84 and 77% and inflammatory cell influx by 66 and 47%, respectively. In contrast, celecoxib (CLX, 10 mg kg(-1), p.o., -1 h) or rofecoxib (RFX, 10 mg kg(-1) , p.o., -1 h) only reduced the Cg-induced pleural exudate volume by 44 and 40%, respectively, but had no significant effect over inflammatory cell influx. At the same doses used for pleurisy, DEX, INDO, CLX, RFX and SC-560 (a selective COX-1 inhibitor, 40 mg kg(-1), p.o., -1 h), inhibited the Cg-induced paw oedema by 49, 31, 21, 21 and 17%. DEX, INDO or SC-560 reduced the level of MPO by 71, 78 and 59%, while CLX or RFX produced a small, but significant increase (28 or 16%) in MPO activity. In the rat model of pleurisy, PGE2 levels in cell-free exudates were significantly attenuated by 91, 89, 57 and 65% in animals treated with DEX, INDO, CLX or RFX. In contrast, INDO reduced significantly the whole bloodTXB, synthesis (59%) while DEX and INDO reduced the pleural content of NOx significantly. Treatment of animals with CLX or RFX did not alter the content of pro-inflammatory cytokines IL-1beta or TNF-alpha in the pleural exudate, but CLX reduced IL-1beta levels in the rat paw tissue and RFX increased TNF-alpha in this tissue. CONCLUSION: Together these results provide consistent evidence indicating that the selective COX-2 inhibitors CLX and RFX, in contrast to DEX, INDO or SC-560, despite reducing greatly the Cg-induced pleural exudation, PGE2 content and paw oedema have only partial acute anti-inflammatory properties in two different rat acute models of inflammation.     

Phase II nonrandomized study of the efficacy and safety of COX-2 inhibitor celecoxib on patients with cancer cachexia

Chronic inflammation is one of the main features of cancer cachexia. Experimental and clinical studies showed that cyclooxygenase-2 inhibitors, such as celecoxib, may be beneficial in counteracting major symptoms of this devastating syndrome. We carried out a prospective phase II clinical trial to test the safety and effectiveness of an intervention with the COX-2 inhibitor celecoxib (300 mg/day for 4 months) on key variables of cachexia (lean body mass, resting energy expenditure, serum levels of proinflammatory cytokines, and fatigue) in patients with advanced cancer at different sites. A sample of 24 patients was enrolled from January to December 2008 and all were deemed assessable. A significant increase of lean body mass and a significant decrease of TNF-α were observed. Moreover, an improvement of grip strength, quality of life, performance status, and Glasgow prognostic score was shown. There were no grade 3/4 toxicities. Patient compliance was very good; no patient had to reduce the celecoxib dosage nor interrupt treatment. Our results showed that the COX-2 selective inhibitor celecoxib is an effective single agent for the treatment of cancer cachexia. Although the treatment of cancer cachexia, a multifactorial syndrome, is more likely to yield success with a multitargeted approach; in the present study, we were able to show that a treatment, such as celecoxib, addressing a single target, albeit very important as chronic inflammation, could have positive effects. Therefore, phase III clinical trials are warranted to test the efficacy and safety of celecoxib.     

COX-2抑制剂对幼鼠反复癎性发作后神经发生的影响

目的:研究环氧合酶-2(COX-2)在癎性发作活化后的表达特点,探讨COX-2抑制剂塞莱昔布(celecoxib,Cel)对癎性活动后海马区神经发生的影响.方法:模型制作:随机将120只体重为50～60 g的3周龄健康Wistar幼鼠分为匹鲁卡品致癎组(EP-Only组)(n=45)和Cel干预致癎组(EP-Cel)(n=45)和生理盐水正常对照组(NS组)(n=30)3组.随机在EP-only及EP-Cel组各取10只匹鲁卡品成功诱导急性发作幼鼠进行腹腔注射溴脱氧尿核苷(BrdU):(1)行为学观察:根据Racine分级评价急性期和慢性期癎性发作行为;(2)形态学检测:各实验组分别在急性发作后第14天,第28天处死大鼠制备组织切片进行免疫组化检测COX-2阳性细胞在各组的表达变化趋势,以及BrdU+神经元特异性核蛋白(NeuN)和BrdU+星形胶质细胞胶原纤维酸性蛋白(GFAP)荧光免疫双标阳性细胞的表达,观察神经前体细胞的增殖及分化在各组的差异.结果:(1)动物行为学观察:在急性期,EP-only组全身性自发反复性癫癎发作(SRS)发作率(90%)明显高于EP-Cel组(56%)(P<0.01);EP-only组癎性发作Racine分级强度(3.7±1.3)明显高于EP-Cel组发作强度(2.5±1.1)(P<0.05);在慢性期,EP-Only组SRS发生率(50%)明显高于EP-Cel组(30%)(P<0.05;X<'2>检验);EP-Only组平均每天SRS发生的频率(1.9±0.58)明显高于EP-Cel组(0.6±0.3)(P<0.01,t检验);(2)形态学检测免疫组化结果:①COX-2免疫反应阳性细胞的表达:匹鲁卡品致癎第14天后,海马区COX-2阳性细胞表达在EP-Only组明显高于EP-Cel组L(158±18)vs(118±20)](P<0.01);②BrdU+NrdU和BrdU+GFAP免疫双标结果:急性期发作第28天后,BrdU+NeuN免疫双标阳性细胞在EP-Only组明显高于EP-Cel组[(36±4)vs(22±3)];同时EP-Only组门区有BrdU+GFAP免疫双标阳性的新生的胶质细胞明显比EP-Cel组高[(26±3)vs(14±2)].结论:COX-2在癎性发作后被迅速诱导表达,COX-2抑制剂Cel能抑制癎性发作激活的异常神经发生和星形胶质细胞增生,减少慢性期SRS.     

COX-2抑制剂对幼鼠反复痫性发作后神经发生的影响

目的：研究环氧合酶-2（COX-2）在痫性发作活化后的表达特点,探讨COX-2抑制剂塞莱昔布（eeleeoxib,Cel）对痫性活动后海马区神经发生的影响。方法：模型制作：随机将120只体重为50～60g的3周龄健康Wistar幼鼠分为匹鲁卡品致痫组（EPOnly组）（n=45）和Cel干预致痫组（EP—Cel）（n=45）和生理盐水正常对照组（NS组）（n=30）3组。随机在EP—only及EP—Cel组各取10只匹鲁卡品成功诱导急性发作幼鼠进行腹腔注射溴脱氧尿核苷（BrdU）：（1）行为学观察：根据Racine分级评价急性期和慢性期痴性发作行为;（2）形态学检测：各实验组分别在急性发作后第14天,第28天处死大鼠制备组织切片进行免疫组化检测COX-2阳性细胞在各组的表达变化趋势,以及BrdU＋神经元特异性核蛋白（NeuN）和BrdU＋星形胶质细胞胶原纤维酸性蛋白（GFAP）荧光免疫双标阳性细胞的表达,观察神经前体细胞的增殖及分化在各组的差异。结果：（1）动物行为学观察：在急性期,EP-only组全身性自发反复性癫痫发作（SRS）发作率（90％）明显高于EP—Cel组（560）（P〈0．01）;EP—only组痫性发作Racine分级强度（3．7±1．3）明显高于EP—Cel组发作强度（2．5±1．1）（P〈0．05）;在慢性期,EP—Only组SRS发生率（500）明显高于EP—Cel组（30％）（P〈0．05;岔检验）;EP—Only组平均每天SRS发生的频率（1．9±0．58）明显高于EP=Cel组（0．6±0．3）（P〈0．01,t检验）;（2）形态学检测免疫组化结果：①COX-2免疫反应阳性细胞的表达：匹鲁卡品致痫第14天后,海马区COX-2阳性细胞表达在EP—Only组明显高于EP-Cel组[（158±18）vs（118±20）]（P〈0．01）;②BrdU＋NeuN和BrdU＋GFAP免疫双标结果：急性期发作第28天后,BrdU＋NeuN免疫双标阳性细胞在EP-Only组明显高于EP—Cel组[（36±4）vs（22±3）];同时EP-Only组门区有BrdU＋GFAP免疫双标阳性的新生的胶质细胞明显比EP—Cel组高[（26±3）vs（14±2）3。结论：COX-2在痂性发作后被迅速诱导表达,COX-2抑制剂Cel能抑制痫性发作激活的异常神经发生和星形胶质细胞增生,减少慢性期SRS。     

Prevention of postoperative adhesion formation in rat uterine horn model by nimesulide: a selective COX-2 inhibitor

BACKGROUND: Pelvic surgery is one of the main causes of intraperitoneal (i.p.) adhesions that create various medical problems including pelvic pain, bowel obstructions and female infertility. A rat model was used to investigate the efficacy of nimesulide, a selective cyclooxygenase-2 inhibitor, in the prevention of adhesion formation. METHODS: Fifty Wistar-Albino rats underwent bilateral uterine horn injury with a unipolar cautery. Study groups were as follows: (i) control group, no adjuvant therapy; (ii) i.p. Ringer's lactate group, 2 ml Ringer's lactate solution was instilled i.p.; (iii) i.p. Ringer's lactate plus nimesulide group, 1 ml Ringer's lactate plus 1 ml nimesulide (0.5 mg/ml) were given i.p.; (iv) intramuscular (i.m.) nimesulide group, 1 ml i.m. nimesulide (0.5 mg/ml) was given preoperatively for 5 days; and (v) i.p. nimesulide group, 1 ml nimesulide (0.5 mg/ml) was instilled i.p. At the end of the study all animals were killed, and a standard adhesion scoring system was applied by a blinded examiner. RESULTS: The mean adhesion extent in study groups was as follows: 1.33 +/- 0.76 in control group, 1.40 +/- 0.90 in i.p. Ringer's lactate group, 0.75 +/- 0.70 in i.p. Ringer's lactate plus nimesulide group, 0.25 +/- 0.44 in i.m. nimesulide group and 0.31 +/- 0.70 in i.p. nimesulide group. The mean +/- SD adhesion severities of control, i.p. Ringer's lactate, i.p. Ringer's lactate plus nimesulide, i.m. nimesulide, and i.p. nimesulide groups were 0.58 +/- 0.35, 0.30 +/- 0.41, 0.27 +/- 0.3, 0.12 +/- 0.28 and 0.15 +/- 0.35 respectively. The lowest adhesions were found in the groups treated with nimesulide i.m. and nimesulide i.p. ( P < 0.05). CONCLUSIONS: This study showed that preoperative i.m. or postoperative i.p. administration of nimesulide to the site of injury reduced the formation of postoperative adhesions in a rat uterine horn model.     

Safety of a specific COX-2 inhibitor in aspirin-induced asthma

In a subset of patients with asthma, aspirin and several other non-steroidal anti-inflammatory drugs (NSAID) that inhibit simultaneously cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) precipitate dangerous asthmatic attacks. We tested the hypothesis that in patients with aspirin-induced asthma the attacks are triggered by inhibition of COX-1 and not COX-2. In twelve asthmatic patients (seven men, five women, average age 39 years) oral aspirin challenge precipitated symptoms of bronchial obstruction with fall in FEV1 > 20%, and a rise in urinary leukotriene E4 (LTE4) excretion; also in five patients the stable metabolite of PGD2, 9alpha11betaPGF2, increased in urine. The patients then entered a double-blind, placebo-controlled, cross-over study in which they received either placebo or rofecoxib in increasing doses 1.5-25.0 mg for 5 consecutive days, separated by a 1-week wash-out period. No patient on rofecoxib developed dyspnoea or fall in FEV1 > 20%; mean urinary LTE4 and 9alpha11betaPGF2 urinary levels, measured on each study day for 6 h post-dosing, remained unchanged. Two patients on placebo experienced moderate dyspnoea without alterations in urinary metabolites excretion. At least 2 weeks after completion of the study, all patients received on an open basis 25 mg rofecoxib without any adverse effects. NSAID that inhibit COX-1, but not COX-2, trigger asthmatic attacks in patients with asthma and aspirin intolerance. Rofecoxib can be administered to patients with aspirin-induced asthma.     

Preventive effect of a galactoglucomannan (GGM) from Dendrobium huoshanense on selenium-induced liver injury and fibrosis in rats

This study was carried out to investigate the preventive effects of galactoglucomannan (GGM), a homogeneous polysaccharide from Dendrobium huoshanense, on liver injury and fibrosis induced by sodium selenite. Sprague–Dawley rats injected subcutaneously with sodium selenite at the dosage of 3.28 mg kg^?1 b. wt. were set as the model groups. Rats treated with sodium selenite at the dosage of 3.28 mg kg^?1 b. wt. and GGM at 50–200 mg kg^?1 b. wt. were set as the prevention groups. Biochemical and histological analysis showed that GGM significantly ameliorated selenite-induced liver injury and fibrosis in rats. Oral administration of GGM effectively attenuated the toxicity of selenite to liver tissue, which was judged both by the decreased activities of serum hepatic enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH), and by liver histopathological examination. Meanwhile, GGM also reduced the levels of H₂O₂ and malondialdehyde (MDA), elevated the levels of GSH, restored the fluidity of hepatic plasma membrane, and retained the activities of endogenous enzymes including superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST). The prevention of selenite-induced liver injury and fibrosis by GGM was further supported by the reduced expression of transforming growth factor-β1 (TGF-β1) and type I collagen. These results suggested that GGM may be developed into a novel antifibrotic agent for the prevention of liver injury and fibrosis.     

Ontogeny of pulmonary cyclooxygenase-1 (COX-1) and -2 (COX-2)

Prostaglandins synthesized by enzymatic reactions such as cyclooxygenases have been implicated in lung pathophysiology. The goal of this study was to delineate the pulmonary ontogeny of cyclooxygenase enzymes (COX-1 and COX-2) immunohistochemical expression and cellular localization in various microanatomic locations of lungs from pre-term, term, and post-natal lambs. Lung tissues were obtained at 115 and 130 days of gestation from pre-term lambs, 145 days (term; complete gestation), and 15 days post-natally. No significant differences were seen in lung COX-1 expression at various microanatomic locations during pre-term, term, or postnatally. Moderate to strong COX-1 expression was present in macrophages, alveolar septa, bronchial smooth muscle cells, bronchiolar smooth muscle cells, vascular endothelial cells, and vascular smooth muscle cells. Minimal COX-1 expression was present in bronchial and bronchiolar epithelial cells. Most microanatomic locations lacked COX-2 expression with the exception of weak expression that was present in bronchial and bronchiolar epithelial cells at 145 days of full gestation and 15 days post-natally. This work suggests that: (a) COX-1 is constitutively expressed in lungs from pre-term, term, and post-natal lambs in various microanatomic pulmonary locations, (b) there is differential expression of COX-1 and COX-2 in the developing lung, and (c) COX-2 does not appear to play a role in lung fetal development, at least in neonatal lambs.     

COX-2抑制剂对幼鼠痫性发作海马神经元突触活动的影响

目的：观察环氧合酶-2（cyclooxygenase-2,COX-2）抑制剂硝基苯-甲磺酸（NS-398）对幼鼠痫样放电的作用及其对海马CA1锥体神经元突触电活动的影响,研究NS-398在幼鼠痫性发作中的作用。方法：用生后第14天龄SD大鼠制作海马组织脑切片,记录其CA1区锥体神经元场电位,以群峰电位（PS）个数和波幅作为指标来评价脑片放电的变化。给脑片用不同浓度青霉素,建立离体海马脑片痂样放电模型,在脑片灌流液中用不同浓度NS-398,观察对PS个数和波幅的影响。全细胞记录模式下,观察NS-398对海马CA1锥体神经元递质释放和突触活动的影响。分别记录自发性兴奋性突触后电流（sEPSC）和自发性抑制性突触后电流（sIPSC）,观察NS-398对其波幅和频率的影响。结果：NS-398浓度为10μmol／L时,对青霉素诱发的痼样放电没有多大的抑制效应;当浓度为20gmol／L时,有明显的抑制作用;为30μmol／L时抑制作用很强,明显降低PS的波幅和减少其频率。NS-398能明显抑制致痴大鼠海马锥体神经元sEPSC的频率,但是对其波幅及衰减时间没有明显的影响;同时NS-398能明显增强致痫大鼠海马脑片锥体神经元sIPSC的频率,明显延长sIPSC的衰减时间,对波幅影响不大。结论：COX-2抑制剂NS-398能减少sEPSC的放电和增强sIPSC的抑制功能,导致兴奋性神经递质的释放减少,降低神经元的兴奋性,从而抑制神经元异常放电。     

Induction of delayed follicular rupture in the human by the selective COX-2 inhibitor rofecoxib: a randomized double-blind study.

BACKGROUND: The aims of the present study were to examine whether periovulatory administration of a cyclo-oxygenase (COX)-2 inhibitor affects human ovulation and endocrine parameters. METHODS: Thirteen healthy women, 30-40 years of age, without hormonal treatment and with regular menstrual cycles (27-34 days), were given the selective COX-2 inhibitor rofecoxib (n = 6) or placebo (n = 7) in a random double-blind fashion. In an initial control cycle, serial hormonal analyses, detection of a measurable mid-cycle urine LH peak and transvaginal ultrasound scans were performed to confirm normal ovulatory and endocrinological cyclic patterns, in all participating women. During the subsequent treatment cycle, serial ultrasound scans were performed. When the dominant follicle reached 14-16 mm in diameter, 25 mg rofecoxib or placebo was taken orally, once daily for 9 consecutive days, during which follicle size was monitored daily by ultrasound scans and serial hormone analyses were performed. RESULTS: Four of the six women who received rofecoxib demonstrated delayed follicle rupture, >48 h after the LH peak, when compared with the placebo group, who all had follicular rupture >36 h after the detected LH peak. No differences in peripheral serum concentrations of progesterone, oestradiol, LH and FSH were observed between placebo and rofecoxib groups, when analysed at specified time intervals. CONCLUSIONS: This study suggests that selective COX-2 inhibition has a negative, local effect on human ovulation, resulting in delayed follicular rupture, without affecting peripheral hormonal cyclicity.     

Nimesulide,a cyclooxygenase-2 (COX-2) inhibitor counteracts immobilization stress-induced alterations in different behavioral and biochemical parameters in mice

There are reports regarding the up-regulation of cyclooxygenase isoenzyme particularly inducible isoform i.e. COX-2 in brain during neurodegenerative or neuropsychiatric disorders. In the present study, we examined the effect of nimesulide (a preferential COX-2 inhibitor) in subchronic immobilization stress. Mice were subjected to immobilization stress for 6 hrs daily for a period of seven days. Nimesulide (2.5 mg/kg, i.p.) was administered daily for 7 days before challenging them to immobilization stress. Behavioral analysis revealed the hyperlocomotor activity and increased anxious response. Subchronic stress decreased % retention of memory and also caused hyperalgesic response in mice. Biochemical analysis revealed that chronic immobilization stress significantly increased lipid peroxidation and nitrite levels and decreased the reduced glutathione and adrenal ascorbic acid levels. Chronic treatment with nimesulide significantly attenuated the immobilization stress-induced behavioral and biochemical alterations. These results suggested that the use of nimesulide could be a useful neuroprotective strategy in the treatment of stress.     

Amelioration of cisplatin-induced rat renal lesions by a cyclooxygenase (COX)-2 selective inhibitor

Cyclooxygenase (COX)-2, an inducible form of COX, plays important roles in inflammatory lesions. We investigated effects of a COX-2 selective inhibitor, NS-398, on cisplatin (CDDP)-induced rat renal lesions. As compared with rats injected with a single dose of CDDP (6 mg/kg; CDDP group), rats who were treated everyday with NS-398 (3 mg/kg) after the CDDP injection (inhibitor group), showed the declines of blood urea nitrogen and creatinine values, and the delay of the peak of regenerating renal epithelial cell number (demonstrable with 5′-bromo-2′-deoxyuridine immunohistochemistry); these findings suggested cytoprotective effects of the inhibitor. Furthermore, the numbers of ED1-immunopositive macrophages and α-smooth muscle actin (α-SMA)-immunopositive myofibroblasts were lower in the inhibitor group than in the CDDP group; mRNA expression of transforming growth factor-β1 (TGF-β1) was also decreased in the inhibitor group. Because the fibrotic area seen after CDDP injection were tended to decrease in the inhibitor group compared with the CDDP group, it was considered that the decreased number of infiltrating macrophages by the inhibitor might lead to the decreased production of TGF-β1, thereby resulting in the reduced number of α-SMA-positive myofibroblasts responsible for fibrosis. Collectively, although these differences between the CDDP and inhibitor groups were not always marked, the COX-2 inhibitor used in this study could ameliorate the CDDP-induced rat renal lesions.