A dose-response study of the effects of biosynthetic human growth hormone on formation and strength of granulation tissue.

The dose-response relationship between biosynthetic human GH (b-hGH) and biomechanical properties (maximum stress, strain at maximum stress, relative failure energy, and maximum stiffness) and collagen deposition of granulation tissue in sc implanted cellulose sponges were investigated after 7 days of implantation in female rats. GH was administered in doses of 0.5, 2.0, and 8.0 mg/kg body weight/day. In the first part of the experiment, treatment with b-hGH started 7 days before implantation of the sponges, in the second part at the day of implantation, and for the 2.0 mg also 2 days before implantation. When b-hGH treatment was started 7 days before implantation, collagen deposition, maximum stress, and maximum stiffness were increased in the sponges from all the hormone-treated groups. In the group treated with 2.0 mg b-hGH/kg body weight.day, also an increase in failure energy was found. When b-hGH treatment was started at the day of implantation or 2 days before implantation, no differences in collagen deposition and biomechanical parameters were found. B-hGH treatment resulted in an increased weight gain in all three groups in the period before implantation, but only 8.0 mg b-hGH/kg body weight resulted in an increased weight gain during the following implantation period. The groups starting hormone treatment at the day of implantation showed an increased weight gain during the implantation period. The study shows that mechanical strength and collagen formation in sc implanted cellulose sponges in rats are increased by b-hGH when treatment is started 7 days before implantation with a maximum increase at a dose of 2.0 mg b-hGH/kg body weight.day.