ACCELERATION of wound healing produced by Mersilk. After an interval of 7 days, called 'the preliminary wounding was first observed by Botsford re-suture interval', the animals were re-anaesthetized, (I941), working in the Wilkie Surgical Research the sutures were removed and the wounds re-opened Laboratory in Edinburgh. The finding was confirmed by blunt dissection to undo any previous healing. by Young, Fisher, and Young (1941)~ Sandblom and These wounds were then re-sutured and termed Muren (1954)~ and Savlov and Dunphy (1954). 'healing secondary wounds'. At the same time as Douglas (1959) found that disrupted and fresh wounds these wounds were re-sutured, four fresh wounds I-cm. WOUND Dried under vacuum and over CaC1, DRIED WOUND I I Homogenized with 0.45 molar NaCl and allowed to stand for 6 days at 4 ' C., then centrifuged I SUPER~ATANT Added C,HSOH to 50 per cent concentration and allowed to stand at 4" C. for 48 hr., then centrifuged I
RES~DUERefluxed with 5-5 per cent TCA at 9o°C. for 6 hr., then centrifuged I PRECIPITATE SUPERNATANT RESIDUE Collagen-hydrolysed Hydrolysed with 6N with 6N HC1 for 16 hr. HC1 for 16 hr. SUPERNATANT HC1 for 16 hr. Hydrolysed with 6N Sol. collagen-hydrolysed with 6N HC1 for 16 hr.Analyses: I, Nitrogen; 2, Proline; 3, Hydroxyproline. FIG. 1.-Diagram of processes involved in chemical fractionations of skin wounds in rabbits, preparatory to estimation of nitrogen, proline, and hydroxyproline.healing simultaneously in the same animal showed different rates of gain of tensile strength. The disrupted wounds healed more quickly than the fresh wounds.The present investigation was designed to study collagen synthesis in disrupted and fresh wounds.
EXPERIMENTAL METHODSFour groups of rabbits were used. In Group I, four initial skin wounds were made on the left side of the back of each of the rabbits and sutured with were made and sutured on the right side of each of the rabbits' backs. These latter wounds were referred to as the ' corresponding primary wounds '. Healing for both these types of wounds is synchronous and considered to start from the day of re-suturing, since any previous healing had been undone on opening the original wounds. These final eight wounds were allowed to heal for 7 days, after which the rabbits were killed by an overdose of nembutal, and strips of the wounds excised using a double-bladed scalpel with blades set I cm. apart. After removing the
