Development of a new delayed healing model of an open skin wound and effects of M-1011G (ointment gauze containing 5% lysozyme hydrochloride) on the model

We tried to develop a new delayed healing model of an open wound made on the dorsal skin of a rat by inducing malnutrition with restriction of food intake. We determined the effects of a newly introduced ointment gauze containing 5% lysozyme hydrochloride (M-1011G) on this model. Malnutrition characterized by a decrease in body weight and serum protein was produced by restricting the daily intake of commercially avail able food to 6 g for 2 weeks without liver disturbance and thereafter maintained with food intake of 12 g/day. Under these conditions, healing of the open wound made on the dorsal skin was prolonged, as compared with that of the wound made on a well-nourished animal. In this model, statistical studies showed that M-1011G was the most effective in accelerating the reduction of the wound area and shortening of the time required for the complete healing, among the following treatments: sterilized gauze alone, ointment gauze alone and 5% lysozyme hydrochloride-containing emulsified ointment. Histological findings showed that M-1011G greatly accelerated the granulation of this tissue which is essential for wound healing, probably due to stimulation of epidermization and regenerated granulation in the wound.