Starting from day 1,the sites of fracture were given different injections for two consecutive days:triple distilled water for groups N and O,and IGF-I for four experimental groups(A 1 ng/kg,B 10 ng/kg,C 100 ng/kg,D 1000 ng/kg).

• 4个实验组注射胰岛素样生长因子-1(A组1ng/kg,B组10ng/kg,C组100ng/kg,D组1000ng/kg)。