REASONS FOR PERFORMING STUDY: There is ample evidence on topographical heterogeneity of the principal biochemical components of articular cartilage over the surface of the joint and the influence of loading thereon, but no information on depth-related zonal variation in horses. OBJECTIVES: To study depth-related zonal variation in proteoglycan (PG) and collagen content in equine articular cartilage. METHODS: Two techniques (safranin-O densitometry and Fourier transform infrared spectroscopy) were applied to sections of articular cartilage from the proximal phalangeal bone of the metacarpophalangeal joint of 18-month-old Thoroughbreds that had been raised at pasture from age 0-18 months without (PASTEX) and with (CONDEX) additional exercise. Two sites were investigated: site 1 at the joint margin that is unloaded at rest or at slow gaits, but subjected to high-intensity loading during athletic activity; and site 2, a continuously, but less intensively, loaded site in the centre of the joint. RESULTS: Proteoglycan values increased from the surface to the deep layers of the cartilage, collagen content showed a reverse pattern. PG content was significantly higher at site 2 in both PASTEX and CONDEX animals without an effect of exercise. In the PASTEX animals collagen content was significantly higher at site 1, but in the CONDEX group the situation was reversed, due to a significant exercise effect on site 1, leading to a reduced collagen content. CONCLUSIONS: Collagen and PG content gradients agree with findings in other species. The observations on PG levels suggest that the exercise level was not strenuous. The collagen results in the PASTEX group confirmed earlier findings, the lower levels at site 1 in the CONDEX group being possibly due to an advancement of the physiological maturation process of collagen remodelling. POTENTIAL RELEVANCE: This study confirms earlier observations that even moderate variations in exercise level in early age may have significant effects on the collagen network of articular cartilage.
REASONS FOR PERFORMING STUDY: There is ample evidence on topographical heterogeneity of the principal biochemical components of articular cartilage over the surface of the joint and the influence of loading thereon, but no information on depth-related zonal variation in horses. OBJECTIVES: To study depth-related zonal variation in proteoglycan (PG) and collagen content in equinearticular cartilage. METHODS: Two techniques (safranin-O densitometry and Fourier transform infrared spectroscopy) were applied to sections of articular cartilage from the proximal phalangeal bone of the metacarpophalangeal joint of 18-month-old Thoroughbreds that had been raised at pasture from age 0-18 months without (PASTEX) and with (CONDEX) additional exercise. Two sites were investigated: site 1 at the joint margin that is unloaded at rest or at slow gaits, but subjected to high-intensity loading during athletic activity; and site 2, a continuously, but less intensively, loaded site in the centre of the joint. RESULTS: Proteoglycan values increased from the surface to the deep layers of the cartilage, collagen content showed a reverse pattern. PG content was significantly higher at site 2 in both PASTEX and CONDEX animals without an effect of exercise. In the PASTEX animals collagen content was significantly higher at site 1, but in the CONDEX group the situation was reversed, due to a significant exercise effect on site 1, leading to a reduced collagen content. CONCLUSIONS: Collagen and PG content gradients agree with findings in other species. The observations on PG levels suggest that the exercise level was not strenuous. The collagen results in the PASTEX group confirmed earlier findings, the lower levels at site 1 in the CONDEX group being possibly due to an advancement of the physiological maturation process of collagen remodelling. POTENTIAL RELEVANCE: This study confirms earlier observations that even moderate variations in exercise level in early age may have significant effects on the collagen network of articular cartilage.
Authors: Petro Julkunen; Esa P Halmesmäki; Jarkko Iivarinen; Lassi Rieppo; Tommi Närhi; Juho Marjanen; Jarno Rieppo; Jari Arokoski; Pieter A Brama; Jukka S Jurvelin; Heikki J Helminen Journal: J Anat Date: 2010-07-14 Impact factor: 2.610
Authors: Arash Hanifi; Xiaohong Bi; Xu Yang; Beril Kavukcuoglu; Ping Chang Lin; Edward DiCarlo; Richard G Spencer; Mathias P G Bostrom; Nancy Pleshko Journal: Am J Sports Med Date: 2012-10-29 Impact factor: 6.202
Authors: Jos Malda; Janny C de Grauw; Kim E M Benders; Marja J L Kik; Chris H A van de Lest; Laura B Creemers; Wouter J A Dhert; P René van Weeren Journal: PLoS One Date: 2013-02-21 Impact factor: 3.240
Authors: Ana Lúcia M Yamada; Marcelo Pinheiro; Marília F Marsiglia; Stefano Carlo F Hagen; Raquel Yvonne A Baccarin; Luís Cláudio L C da Silva Journal: J Vet Sci Date: 2020-05 Impact factor: 1.672
Authors: Anouk M Barendregt; Valentina Mazzoli; J Merlijn van den Berg; Taco W Kuijpers; Mario Maas; Aart J Nederveen; Robert Hemke Journal: Pediatr Radiol Date: 2019-11-09