Evaluation of the catabolic activity of cartilage by measurement of serum keratan sulfate concentration in foals.
OBJECTIVE
To determine keratan sulfate (KS) concentration in the serum of foals at the early stage of growing, and to evaluate the role of serum KS as a cartilage catabolic marker, comparing its values with the fluctuation of serum alkaline phosphatase (ALP) activity as a measurement of osteoblastic activity.


METHODS
12 foals with normal growth and 3 foals with joint abnormalities within 18 months after birth.


METHODS
Measurement of KS concentration and ALP activity in serum and radiographic and physical examinations were done.


RESULTS
In all foals, serum KS concentration was high from 1 week after birth to 3 months of age, while serum ALP decreased with aging. The value started to decrease rapidly from 3 to 5 months of age, then gradually reached adult values. During the first 3 months, KS concentration in male foals was significantly higher than that in female foals. In 3 foals which had joint problems, KS concentration was higher than that in normally growing foals at 1 week, and at 1, 2, and 3 months of age.


CONCLUSIONS
Cartilage catabolic activity is higher in developing foals up to 3 months of age, suggesting that the immature joint at this time could be easily affected by any factor of loading. Moreover, though only 3 diseased foals were examined, higher serum KS concentration in these foals suggest that this variable might be a useful measure of joint diseases, even at an early stage of life in foals.
Okumura
M
M
Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Fujinaga
T
T
Urakawa
E
E
Tagami
M
M
Tsukiyama
K
K
D000375:Aging / Q000502:physiology*; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D015415:Biomarkers / Q000097:blood; D002356:Cartilage / Q000254:growth & development / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006736:Horses / Q000002:abnormalities / Q000254:growth & development*; D007596:Joints / Q000002:abnormalities / Q000254:growth & development; D007632:Keratan Sulfate / Q000097:blood*; D008297:Male; D010006:Osteoblasts / Q000378:metabolism; D012727:Sex Characteristics
D015415:Biomarkers; D007632:Keratan Sulfate; D000469:Alkaline Phosphatase