Ovariectomized rats as a model of postmenopausal osteoarthritis: validation and application

We aimed to assess the effect of ovariectomy on cartilage turnover and degradation, to evaluate whether ovariectomized (OVX) rats could form an experimental model of postmenopausal osteoarthritis. The effect of ovariectomy on cartilage was studied using two cohorts of female Sprague–Dawley rats, aged 5 and 7 months. In a third cohort, the effect of exogenous estrogen and a selective estrogen receptor modulator was analyzed. Knee joints were assessed by histological analysis of the articular cartilage after 9 weeks. Cartilage turnover was measured in urine by an immunoassay specific for collagen type II degradation products (CTX-II), and bone resorption was quantified in serum using an assay for bone collagen type I fragments (CTX-I). Surface erosion in the cartilage of the knee was more severe in OVX rats than in sham-operated animals, particularly in the 7-month-old cohort (P = 0.008). Ovariectomy also significant increased CTX-I and CTX-II. Both the absolute levels of CTX-II and the relative changes from baseline seen at week 4 correlated strongly with the severity of cartilage surface erosion at termination (r = 0.74, P < 0.01). Both estrogen and the selective estrogen receptor modulator inhibited the ovariectomy-induced acceleration of cartilage and bone turnover and significantly suppressed cartilage degradation and erosion seen in vehicle-treated OVX rats. The study indicates that estrogen deficiency accelerates cartilage turnover and increases cartilage surface erosion. OVX rats provide a useful experimental model for the evaluation of the chondroprotective effects of estrogens and estrogen-like substances and the model may be an in vivo representation of osteoarthritis in postmenopausal women

Detection of specific nitrated markers

publication date: 2012-12-11; filing date: 2011-08-3

DETECTION OF SPECIFIC NITRATED MARKERS

publication date: 2004-12-22; filing date: 2003-03-12Methods are described for improving the diagnostic possibilities of diseases where oxidative NO-modifications occur, for example inflammatory conditions, cancer, Parkinson's or Alzheimer's disease, and to provide means of monitoring the effects of therapeutical measures taken towards such diseases. The invention enables the detection of disease specific catabolic markers related to oxidative NO-modifications, utilizing an immunoassay comprising antibodies directed against nitrated and non-nitrated epitopes characteristic of a specific protein

METHOD FOR MONITORING COLLAGEN TYPE II DEGRADATION IN CARTILAGE

publication date: 2004-12-15; filing date: 2003-03-12A method for improving the diagnostic assessment of cartilage degenerative processes, and to provide means of monitoring the effects of therapeutical measures taken towards arthritic diseases in most mammals ultizes an immunoassay to detect fragments of collagen type II resulting from collagenase activity comprising an antibody directed against an epitope comprised in the amino acid sequence HRGYPGLDG, located in the helical region of collagen type II