AIM:To investigate the curative effects of oral and nasaladministration of chicken type Ⅱ collagen(CⅡ)on adjuvantarthritis(AA)in rats with meloxicam-induced intestinallesions.METHODS:AA model in Sprague-Dawley(SD)rats withor without intestinal lesions induced by meloxicam wasestablished and those rats were divided randomly into sixgroups which included AA model,AA model+meloxicam,AA model+oral CⅡ,AA model+nasal CⅡ,AA model+meloxicam+oral C Ⅱ and AA model+meloxicam+nasal CⅡ(n=12).Rats was treated with meloxicam intragastricallyfor 7 d from d 14 after immunization with complete Freund’sadjuvant(CFA),and then treated with chicken CⅡintragastrically or nasally for 7 d.Histological changes ofright hind knees were examined.Hind paw secondaryswelling and intestinal lesions were evaluated.Synoviocyteproliferation was measured by 3-(4,5-dimethylthiazol-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide(MTT)method.Activities of myeloperoxidase(MPO)and diamineoxidase(DAO)from supernatants of intestinal homogenateswere assayed by spectrophotometric analysis.RESULTS:Intragastrical administration of meloxicam(1.5 mg/kg)induced multiple intestinal lesions in AA rats.There was a significant decrease of intestinal DAO activitiesin AA+meloxicam group(P<0.01)and AA model group(P<0.01)compared with normal group.DAO activities ofintestinal homogenates in AA+meloxicam group weresignificantly less than those in AA rats(P<0.01).Therewas a significant increase of intestinal MPO activities inAA+meloxicam group compared with normal control(P<0.01).Oral or nasal administration of CⅡ(20 μg/kg)could suppress the secondary hind paw swelling(P<0.05for oral CⅡ;P<0.01 for nasal CⅡ),synoviocyte proliferation(P<0.01)and histopathological degradation in AA rats,butthey had no significant effects on DAO and MPO changes.However,oral administration of CⅡ(20 μg/kg)showed thelimited efficacy on arthritis in AA+meloxicam model andthe curative effects of nasal CⅡ(20 μg/kg)were shown tobe more efficient than that of oral CⅡ(20 μg/kg)both inAA model and in AA+meloxicam model(P<0.05).CONCLUSION:Oral administration of CⅡ shows the limitedefficacy on arthritis in AA rats with intestinal lesions,andnasal administration of CⅡ is more efficient than oraladministration of CⅡ to induce mucosal tolerance in AA rats. Zheng YQ,Wei W,Shen YX,Dai M,Liu LH.Oral and nasaladministration of chicken type Ⅱ collagen suppresses adjuvantarthritis in rats with intestinal lesions induced by meloxicam.WorldJ Gastroenterol 2004;10(21):3165-3170http://www.wjgnet.com/1007-9327/10/3165.asp AIM: To investigate the curative effects of oral and nasaladministration of chicken type II collagen (CII) on adjuvantarthritis (AA) in rats with meloxicam-induced intestinal lesions. METHODS: AA model in Sprague-Dawley meloxicam waststablished and those rats were divided randomly into sixgroups which included AA model, AA model + meloxicam, AA model + oral C Ⅱ, AA model + nasal C Ⅱ, AA model + meloxicam + oral C Ⅱ and AA model + meloxicam + nasal CⅡ (n = 12). Rats was treated with meloxicam intragastrically for 7 d from d 14 after immunization with complete Freund’s adjuvant (CFA), and then treated with chicken C Ⅱ intact or nasally for 7 d. Histological changes of right hind knees were examined. Hind paw secondaryswelling and intestinal lesions were evaluated. Synoviocyteproliferation was measured by 3- (4,5-dimethylthiazol-2-thiazolyl) -2,5-diphenyl-2H tetrazolium bromide (MTT) ants of intestinal homogenateswere assayed by spectrophotometric analysis .RESULTS: Intragastrical administration of meloxicam (1.5 mg / kg) induced multiple intestinal lesions in AA rats. There was a significant decrease of intestinal DAO activitiesin AA + meloxicam group (P <0.01) and AA model (P <0.01) compared with normal group. DAO activities ofintestinal homogenates in AA + meloxicam group weresignificantly less than those in AA rats (P <0.01) .There was a significant increase of intestinal MPO activities inAA + meloxicam group compared with normal control ( P <0.01). Oral or nasal administration of CⅡ (20 μg / kg) could suppress the secondary hind paw swelling (P <0.05for oral CⅡ; P <0.01 for nasal CⅡ), synoviocyte proliferation in AA rats, but the had no significant effects on DAO and MPO changes. However, oral administration of CII (20 μg / kg) showed the limited efficacy on arthritis in AA + meloxicam model and the curative effects of nasal CII shown t obe more efficient than that of oral CII (20 μg / kg) both in AA model and in AA + meloxicam model (P <0.05) .CONCLUSION: Oral administration of CII shows the limitedefficiency on arthritis in AA rats with intestinal lesions, andnasal administration of CII is more efficient Zheng YQ, Wei W, Shen YX, Dai M, Liu LH. Oral and nasaladministration of chicken type II collagen suppresses adjuvantarthritis in rats with intestinal lesions induced by meloxicam. World J Gastroenterol 2004; 10 (21): 3165-3170http: //www.wjgnet.com/1007-9327/10/3165.asp