Acta physiol. scand. 1979. 105. 114-116 From the Department of Surgey, Central Hospital of Molndal, and Department of Surgey 111, University of Goteborg, Sweden
A healing promoting factor in rat wound fluid BY HUGOLUNDBORG
The origin and nature of stimulus to cells and tissues to repair after an injury is incompletely known. The stimulation for wound-healing may be due to a positive, healing-promoting factor. Such substances may be formed and released either systemically or locally. The aim of the present study was to examine whether a healing-promoting factor is formed or not, and, in the former case, if it increases the tensile strength. This may be used as a measurable indicator of the extent of the repair of the tissue injured (Howes, Sooy and Harvey 1929, Sandblom, Petersen and Muren 1953). Fluid produced in a stainless wire mesh cylinder, subcutaneously implanted, is used as interstitial wound fluid (Schilling, Joel and Shurley 1959, Hunt et al. 1967). If a stimulating factor is liberated locally, it may exist in this fluid. The tensile strength of wounds to which such fluid was added, was determined. An increase would indicate the presence of a healingpromoting factor. The formation of granulation tissue of the healing wound is considered to increase when a stimulating factor exists. Therefore, cellulose sponges were implanted in wounds to test this effect, assuming that increases in weight are due to stimulation of connective tissue formation (Grindlay and Wangh 1951). Rabbits weighing about 3 kg were used. The animals were anesthesized with N e b u m a P (30 mg/kg b.wt.). Two incisions about 2 c m long were made o n each side of the middle line of the back. Through each incision a stainless wire mesh cylinder (5 cm long and 2 cm in diameter) was implanted S.C. T h e incision was closed by single silk suture (3/0).One week later, the cylinder was punctured and the fluid collected a n d used a s wound fluid. Serum was received by puncture of ear veins of rabbits. 3 longitudinal skin incisions of a length of 4 cm a n d reaching underlying muscular fascia were made o n each side of the back of rabbits a t a distance of 2.5 cm from the middle line. 2 ml of serum was added to the wounds on one side, and 2 ml of the wound fluid t o the contralateral wounds. T h e wounds were closed by 3/0 silk. The tensile strength of the wounds were determined by the method described by Sandblom et al. (1953) one week after the incision. The rabbit was anesthesized and the sutures removed prior t o the measurement. The wound was ruptured o n either side of i t . T w o determinations were made of t h e tensile strength of each wound. Viscose cellulose sponges 10 x 10 x 20 m m (Visella Sateri Oy., Valkeakoski, Finland) were divided into two equal parts and immediately sewn together with a silk suture. T h e pair implanted in each animal were of about the same weight. T h e animals were anesthesized with ether a n d two symmetrical incisions close to the midline of the back were made. A S.C. pocket was dissected in each wound. The cellulose sponges had been soaked in serum o r wound fluid prior t o the implantation in the pockets. Each animal got a serumtreated sponge o n one of the pockets and a wound fluid-treated sponge in the other.
114
WOUND HEALING PROMOTING FACTOR
115
TABLEI
T.S.
Significance
N
WF Control
553 & 25 466+ 25
pi- 0.01 < 0.02
68 68
WF Serum
454221 418& 19
p>0.20
A healing promoting factor in rat wound fluid BY HUGOLUNDBORG
The origin and nature of stimulus to cells and tissues to repair after an injury is incompletely known. The stimulation for wound-healing may be due to a positive, healing-promoting factor. Such substances may be formed and released either systemically or locally. The aim of the present study was to examine whether a healing-promoting factor is formed or not, and, in the former case, if it increases the tensile strength. This may be used as a measurable indicator of the extent of the repair of the tissue injured (Howes, Sooy and Harvey 1929, Sandblom, Petersen and Muren 1953). Fluid produced in a stainless wire mesh cylinder, subcutaneously implanted, is used as interstitial wound fluid (Schilling, Joel and Shurley 1959, Hunt et al. 1967). If a stimulating factor is liberated locally, it may exist in this fluid. The tensile strength of wounds to which such fluid was added, was determined. An increase would indicate the presence of a healingpromoting factor. The formation of granulation tissue of the healing wound is considered to increase when a stimulating factor exists. Therefore, cellulose sponges were implanted in wounds to test this effect, assuming that increases in weight are due to stimulation of connective tissue formation (Grindlay and Wangh 1951). Rabbits weighing about 3 kg were used. The animals were anesthesized with N e b u m a P (30 mg/kg b.wt.). Two incisions about 2 c m long were made o n each side of the middle line of the back. Through each incision a stainless wire mesh cylinder (5 cm long and 2 cm in diameter) was implanted S.C. T h e incision was closed by single silk suture (3/0).One week later, the cylinder was punctured and the fluid collected a n d used a s wound fluid. Serum was received by puncture of ear veins of rabbits. 3 longitudinal skin incisions of a length of 4 cm a n d reaching underlying muscular fascia were made o n each side of the back of rabbits a t a distance of 2.5 cm from the middle line. 2 ml of serum was added to the wounds on one side, and 2 ml of the wound fluid t o the contralateral wounds. T h e wounds were closed by 3/0 silk. The tensile strength of the wounds were determined by the method described by Sandblom et al. (1953) one week after the incision. The rabbit was anesthesized and the sutures removed prior t o the measurement. The wound was ruptured o n either side of i t . T w o determinations were made of t h e tensile strength of each wound. Viscose cellulose sponges 10 x 10 x 20 m m (Visella Sateri Oy., Valkeakoski, Finland) were divided into two equal parts and immediately sewn together with a silk suture. T h e pair implanted in each animal were of about the same weight. T h e animals were anesthesized with ether a n d two symmetrical incisions close to the midline of the back were made. A S.C. pocket was dissected in each wound. The cellulose sponges had been soaked in serum o r wound fluid prior t o the implantation in the pockets. Each animal got a serumtreated sponge o n one of the pockets and a wound fluid-treated sponge in the other.
114
WOUND HEALING PROMOTING FACTOR
115
TABLEI
T.S.
Significance
N
WF Control
553 & 25 466+ 25
pi- 0.01 < 0.02
68 68
WF Serum
454221 418& 19
p>0.20
