Effects of trauma and partial devascularization on protein synthesis in the avian flexor profundus tendon

Destruction of the blood supply to tendons adversely affects healing of repaired flexor tendons. In cut and sutured avian flexor profundus tendons, protein synthesis was maximal on Day 10 post-trauma with a broad peak that spanned at least 12 days. Partial devascularization of cut-sutured tendons reduced protein synthesis to 43% of the value for nondevascularized-cut-sutured tendons on Day 10. Both collagen and noncollagen protein synthesis in cut-sutured tendons followed a bimodal pattern with peaks on postoperative Days 10 and 18. Collagen and noncollagen protein synthesis in partially devascularized tendons was decreased. Relative collagen synthesis, that is, the amount of collagen produced compared with the amount of all other proteins produced at the same time, was increased (Days 10 to 15) in the tendons that were cut-sutured and partially devascularized. The latter observations indicate that: 1) cutting a tendon results in increased protein synthesis; 2) partial devascularization of the cut tendon results in a lesser increase in protein synthesis; and 3) although overall protein synthesis, and collagen synthesis in particular, are reduced in partially devascularized, healing tendons, the relative amount of collagen produced is increased, emphasizing the importance of collagen to the healing tendon during the time of maximum synthesis.