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ABSTRACT. Effects of the collagen oligopeptide (COP) were examined by its repeat injection into the inflammatory rabbit Achilles tendon (Tendo calcaneus communis), in which tenositis was induced by injection of bacterial collagenase. COP was evaluated 5 times over a period of 3 weeks to 1 month after injection of collagenase. At 1 month after treatment, the therapeutic effect of COP was evaluated by examining the structure of collagen fibrils, amount and components of glycosaminoglycans (GAGs) and matrix metalloproteinases (MMPs), and compared with the saline injection, control, and normal groups. The Achilles tendon of rabbit in the control group (no COP injection) and saline injection group showed a notable increase in the number of fine collagen fibrils, a change in GAG composition and increase in the amount of pro-MMP-2, indicating the weakening of the tendon. In contrast, the size distribution of collagen fibrils, GAG composition and the amount of pro-MMP-2 was similar to those in the normal group. These results suggest that COP injection promotes healing processes of the tendon injury. KEY WORDS: collagen fibril, collagen oligopeptide, electron microscopy, glycosaminoglycans, rabbit tendon.J. Vet. Med. Sci. 70(12): 1295-1300, 2008 The basic function of a tendon is to convey the force exerted by a muscle to the bone. The mechanical load is not transmitted directly to the bone because tendon is a highly flexible connective tissue. This connective tissue is composed of two components: tendon cells and extracellular matrix (ECM) that consists of collagen and proteoglycans [1,21]. Collagen in a tendon is composed of mainly type I collagen and is arranged into bundles of collagen fibrils that are further organized into tendon fascicles [22]. Proteoglycan has its core protein covalently bound to glycosaminoglycan (GAG). GAG is a non-branched polysaccharide consisting of repeated units of amino acids and uronic acids. GAGs in ECM exist as proteoglycans except for hyaluronic acid (HA) that exists as a free GAG. Proteoglycans are classified into chondroitin sulphate (CS), dermatan sulphate (DS), heparan sulphate (HS), heparin or keratan sulphate according to their uronic acid subunit [3]. Decorin is the most abundant DS proteoglycan in tendon, and is reportedly involved in both the formation of collagen fibrils and adjustment of collagen fibril diameter [37]. However, its role in the turnover of tendon ECM has not yet been elucidated [16].Matrix metalloproteinase (MMP) is an enzyme that has zinc ion in its active core and requires calcium ion for maintenance of the activity. More than 20 types of MMP have been reported so far, and they play an important role in the turnover of tendon ECM [7,34]. MMPs are divided into the following types: collagenase (MMP-1, -8, -13), gelatinase (MMP-2, -9), stromelysin (MMP-3, -10), membrane , and others (including MMP-7, -11, -12) according to their biochemical properties [4]. However, how these MMPs are involved in the turnover of tendon ECM remains unclear.Inflammation of a tendo...

This report describes the first clinical case, to our knowledge, of a dog with polyglandular deficiency syndrome with diabetes mellitus and hypoadrenocorticism. A six-year-old female Cavalier King Charles Spaniel presented with a history of lethargy and appetite loss. The dog was diagnosed with diabetic ketoacidosis based on hyperglycemia and renal glucose and ketone body loss. The dog’s condition improved on intensive treatment of diabetes mellitus; daily subcutaneous insulin detemir injection maintained an appropriate blood glucose level over half a year. However, the dog’s body weight gradually decreased from day 207, and on day 501, it presented with a decreased appetite; the precise cause could not be determined. Based on mild hyponatremia and hyperkalemia, hypoadrenocorticism was suggested; the diagnosis was made using an adrenocorticotropic hormone stimulation test. Daily fludrocortisone with low-dose prednisolone oral administration resulted in poor recovery of the blood chemistry abnormalities; however, monthly desoxycorticosterone pivalate (DOCP) subcutaneous injection with daily low-dose prednisolone oral administration helped in the significant recovery of the abnormalities. Therefore, clinicians should consider the possibility of coexistence of hypoadrenocorticism in dogs with diabetes mellitus presenting with undifferentiated weight loss. Additionally, DOCP (not fludrocortisone) may be useful in treating dogs with diabetes mellitus complicated with hypoadrenocorticism.