Influence of biosynthetic human growth hormone on biomechanical properties of rat skin incisional wounds.

The influence of biosynthetic human growth hormone (b-hGH) on the mechanical properties (maximum stress, 'relative failure energy', maximum stiffness, strain at maximum stress) of incisional wounds in rat skin was investigated after 4, 7 and 10 days of healing. Tests for each healing period comprised one group of rats given b-hGH (2.0 mg/kg/day, subcutaneously) for 7 days before wounding and another group with treatment begun on the day of wounding. Control rats were given isotonic saline. After each healing period, standardized skin strips were cut out perpendicular to the wound, their dimensions measured and mechanical strength tested in a special machine. When 4-day healing was preceded by 7-day b-hGH treatment, the values for maximum stress, relative failure energy and maximum stiffness were, respectively, 56%, 49% and 46% higher than in control wounds. No such difference was found when treatment started on the day of wounding. After 7-day and 10-day healing no difference in mechanical properties was found between the hormone-treated groups and the controls.