[Comparative studys on ages-related changes in collagen structures of Achilles and tail tendons in rats].

The rate and degree of age changes in collagen structures of the Achilles and tail tendons were studied in 0.5, 1, 3, 12 and 24 month old rats. The hydration degree and imino acid content were determined in the tendon collagen fibres. The proline/hydroxyproline ratio and collagen content in tendons were calculated. The wide-angle X-ray studies in the air-dried samples obtained from collagen fibres were conducted for estimating orientation and texture degree of collagen fibres. By all the studied parameters the formation and development of collagen structures in the Achilles tendons are more rapid and intensive than in the tail ones.