Collagen in Granulation tissues
- 26 Downloads
Collagen is abundantly synthesized in granulation tissues and reaches a concentration higher than in normal neighbouring tissues. Such newly formed collagen is characterized by an abnormally low solubility and an easy degradation by collagenases and collagenolytic cathepsins. The activities of these two types of enzymes are high (especially collagenases) in tissues of acute inflammations when the granuloma is resorbing. These activities are lower in subacute inflammation and the collagen content of the persistent granuloma remains high.
The collagen synthesized in granulation tissues is cross linked by hydroxylysino-5-keto-norleucine, the stable cross-link of collagen in embryonic skin. It is progressively replaced by the two aldimine cross links of normal adult skin when the granuloma is resorbed (acute inflammations induced in rats; human normal scars). The cross link of embryonic skin, on the contrary, is permanently present in collagen of tissues of subacute, chronic inflammations (sponge implants in rats, human hypertrophic scars and keloids).
Studies of the structure of α-chains revealed that type III collagen (embryonic collagen) is present in granulation tissues.
KeywordsCollagen Collagenase Granulation Tissue Cross Link Acute Inflammation
Unable to display preview. Download preview PDF.
- A.J. Bailey, C.M. Peach and L.J. Fowler,Chemistry of the collagen cross-links, Bioch. J.117, 819–831 (1970).Google Scholar
- A.J. Bailey and S.P. Robins,Embryonic skin collagen: replacement of the type of aldimine cross-links during the early growth period, F.E.B.S. Letters21, 330–333 (1972).Google Scholar
- S. Bazin and A. Delaunay,Biochimie de l'Inflammation. VI. Fluctuations du taux du collagène et des protéines non fibrillaires dans différents types de foyers inflammatoires, Ann. Inst. Pasteur107, 163–172 (1964).Google Scholar
- S. Bazin and A. Delaunay,Variations de l'activité collagénolytique dans des foyers inflammatoires en évolution, Ann. Inst. Pasteur110, 347–354 (1966).Google Scholar
- S. Bazin and A. Delaunay,The properties of collagen in tissues of penicillamine treated rats, in:Chemistry and Molecular Biology of the Intercellular Matrix, vol. 1 (Ed. E.A. Balazs; Academic Press, 1970), p. 449–456.Google Scholar
- S. Bazin and A. Delaunay,Biochimie de l'Inflammation. IX. Etude chimique et physiologique de deux cathepsines isolées de foyers inflammatoires, Ann. Inst. Pasteur120, 50–61 (1971).Google Scholar
- S.M. Fitch, M.L.H. Harkness and R.D. Harkness,Extraction of collagen from tissues, Nature176, 163–164 (1955).Google Scholar