<p>This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</p> <p>Nonenzymatic glycation of connective tissue matrix proteins
is a major contributor to the pathology of diabetes
and aging. Previously the author and colleagues have shown
that nonenzymatic glycation significantly enhances the matrix
stability in the Achilles tendon (Reddy et al., 2002,
<italic>Arch. Biochem. Biophys.</italic>, 399, 174–180). The present study
was designed to gain further insight into glycation-induced
collagen cross-linking and its relationship to matrix stiffness
in the rabbit Achilles tendon. The glycation process
was initiated by incubating the Achilles tendons (n = 6) in
phosphate-buffered saline containing ribose, whereas control
tendons (n = 6) were incubated in phosphate-buffered
saline without ribose. Eight weeks following glycation, the
biomechanical attributes as well as the degree of collagen
cross-linking were determined to examine the potential associations
between matrix stiffness and molecular properties
of collagen. Compared to nonglycated tendons, the
glycated tendons showed increased maximum load, stress,
strain, Young's modulus of elasticity, and toughness indicating
that glycation increases the matrix stiffness in the
tendons. Glycation of tendons resulted in a considerable decrease
in soluble collagen content and a significant increase
in insoluble collagen and pentosidine. Analysis of potential
associations between the matrix stiffness and degree of collagen
cross-linking showed that both insoluble collagen and
pentosidine exhibited a significant positive correlation with
the maximum load, stress, and strain, Young's modulus of
elasticity, and toughness (<italic>r</italic> values ranging from .61 to .94) in the Achilles tendons. However, the soluble collagen content
present in neutral salt buffer, acetate buffer, and acetate
buffer containing pepsin showed an inverse relation
with the various biomechanical attributes tested (<italic>r</italic> values
ranging from .22 to .84) in the Achilles tendons. The results
of the study demonstrate that glycation-induced collagen
cross-linking is directly associated with the increased matrix
stiffness and other mechanical attributes of the tendon.</p>
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Exp Diabesity Res. 2004; 5(2):143-153