Protein synthesis by granulation tissue in bipedicle tube flaps

The protein synthesis and the collagen synthesis by 2- to 7-week-old granulation tissue from implanted cylinders in bipedicle tube flaps on rabbits were measured in vitro by the incorporation of 14C-proline in proteins and in collagen hydroxyproline. Granulation tissue from cylinders implanted in skin folds were used as controls. In the skin flap group the protein synthesis was high at week 2, after which it decreased to week 5. In the controls the protein synthesis was the same as in the skin flap group at week 2. A decrease occurred between weeks 2 and 4 and a further decrease between weeks 6 and 7. At weeks 5 and 6 the protein synthesis was higher in the controls than in the skin flap group, but at week 7 it was the reverse. The collagen synthesis was high and equal in both groups at weeks 2 and 3 and then decreased to weeks 4 and 5. Between weeks 6 and 7 a further decrease was found in the controls, but not in the skin flap group.