Alterations to cell metabolism in connective tissues of the knee after ovariohysterectomy in a rabbit model: are there implications for the postmenopausal athlete?
BACKGROUND
Participation in regular exercise and athletic activities across the lifespan is encouraged to maintain the cardiovascular and musculoskeletal systems and general wellbeing. Before the menopause there is an increased risk of anterior cruciate ligament (ACL) injuries in female athletes, whereas there is an increased risk of joint diseases such as knee osteoarthritis after the menopause. Although there are few data regarding alterations in individual connective tissues of the knee in humans either before, during or after the menopause, it is possible to assess changes in experimental models following surgical menopause.


OBJECTIVE
To assess changes in cell metabolism in the medial collateral ligament, ACL, patellar tendon, lateral and medial menisci, tibial plateau and femoral condyle articular cartilage and the synovium after surgical menopause in an experimental model system.


METHODS
Panels of rabbits were subjected to ovariohysterectomy or sham operations, and RNA from each tissue was assessed for collagen, proteoglycan, proteinase, growth factor, sex hormone receptor and inflammatory mediator messenger RNA levels by reverse transcribed PCR.


RESULTS
Unique alterations in cell metabolism were detected 2 months after surgical menopause and the pattern of significant changes was tissue specific (number of mRNA species altered, extent of changes, elevation/depression of changes).


CONCLUSIONS
Changes in cell metabolism may alter the set point for the tissues of the knee and subsequently the functioning of the knee after the menopause. Such changes may contribute to an increased risk of injury and/or degenerative conditions. Further studies in pre and postmenopausal women athletes may also shed light on whether the present findings can be extrapolated to human populations.
Hart
D A
DA
McCaig Institute for Bone and Joint Health, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta, Canada T2N 4Z6. hartd@ucalgary.ca
Achari
Y
Y
D000818:Animals; D003094:Collagen / Q000378:metabolism; D003238:Connective Tissue / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D007044:Hysterectomy; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D023421:Models, Animal; D010052:Ovariectomy; D010447:Peptide Hydrolases / Q000378:metabolism; D017698:Postmenopause / Q000378:metabolism*; D011817:Rabbits; D013177:Sports / Q000502:physiology*; D013264:Stifle / Q000378:metabolism*
D016207:Cytokines; D036341:Intercellular Signaling Peptides and Proteins; D003094:Collagen; D010447:Peptide Hydrolases