Enzymatic changes in the healing rat achilles tendon

The tenotomized rat Achilles tendon has been used as a medium to study the biochemical response of tendons to injury. Injury to one part of the tendon produces changes characteristic of repair throughout the entire length of the tissue. During the first 12–36 hr following tenotomy, glycolysis, the pentose shunt, and the citric-acid-cycle enzymes are stimulated throughout the tendon, with enrichment of marker enzymes associated with new collagen and mucopolysaccharide formation. The most significant changes in these enzyme patterns and in the levels of lysosomal enzymes changes which are indicative of repair or remodeling of the tendon occurred during the first 6 weeks following injury and are most marked near the site of tenotomy.