Stabilization of collagen fibres during development and through growth to maturation has now become fairly documented. In vitro effect of mechanical stretching of rats skin on oxidative deamination of ε-NH2-groups of lysine and hydroxylysine, and functional properties of its type І collagen were studied. Experiments were carried out on the skin of a 3-months old male Wistar rat weighing about 800 mg. The skin tissue was divided into four (4) and subjected to different mechanical stresses in Ringer-Krebs medium for 6 hours at 37 oC. The Degree of oxidative deamination of lysine and hydroxylysine was evaluated by way of the content of free ε-amino (ε-NH2) and aldehyde (COH) groups. Level of covalent cross-linking of collagen in skin samples was assessed by its solubility in 1 M solution of NaCl and expressed as a percentage of total collagen content in the tissue. Collagen synthesized under the influence of mechanical stretching had higher content of free ε-NH2-groups and lower level of inter-molecular cross-links compared to the collagen synthesized without the stretching. This finding may indicate that fibrils formed in the former were shorter and had lower thermal stability due to a decrease in the degree of cross linkages.
Key words: Connective tissue, collagen, cross-linkage, fibril, mechanical stretching, oxidative deamination, thermal stability.
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