title: Cross-relaxation times of normal and biochemically induced osteoarthritic rabbit knee cartilages.
abstract: We measured the spin-lattice relaxation times (T1) of water protons and intermolecular cross-relaxation times (T(IS)) from irradiated protein protons (f2-irradiation at 1.95 or -4.00 ppm) of rabbit normal and monoiodoacetate-induced degenerated knee articular cartilages to observed water protons. The mean values of T1 (T1) for control and degenerated rabbit knee cartilages were 1.87+/-0.15 (mean+/-SD, n=29) and 1.82+/-0.13 s (n=34), respectively. The mean values of water content (W(H2O)) for control and degenerated rabbit knee cartilages were 82.9+/-2.09 (n=26) and 83.1+/-2.57% (n=28), respectively. These values were not statistically different from each other. However, the mean values of T(IS) (T(IS)) for normal knee articular cartilage were significantly different from those for degenerated cartilage: (normal), T(IS) (f2=1.95 ppm)=2.46+/-0.62 s (n=28), T(IS) (f2=-4.00 ppm)=4.25+/-1.26 s (n=26); (degenerated), T(IS) (f2=1.95 ppm)=1.99+/-0.76s (n=34), T(IS) (f2=-4.00 ppm)=3.33+/-0.76 s (n=31). Obtained results may be attributed to the reported switchover from type II to type I collagen syntheses in osteoarthritic cartilage, resulting in broad collagen fibers. This specificity of cross-relaxation effect may prove useful in the noninvasive and pathophysiological evaluation of cartilage tissues in vivo.
authors.affiliation: Department of Physiology, Gifu University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kuwata
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: S
authors.initials: S
authors.lastname: Era
authors.forename: M
authors.initials: M
authors.lastname: Sogami
authors.forename: K
authors.initials: K
authors.lastname: Kida
authors.forename: T
authors.initials: T
authors.lastname: Iwama
authors.forename: K
authors.initials: K
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Matsunaga
authors.forename: H
authors.initials: H
authors.lastname: Watari
mesh_terms: D000818:Animals; D001834:Body Water / Q000378:metabolism; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology*; D007461:Iodoacetates; D019807:Iodoacetic Acid; D007719:Knee Joint / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010003:Osteoarthritis / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D011817:Rabbits; D012016:Reference Values
chemical_list: D007461:Iodoacetates; D019807:Iodoacetic Acid