Effect of growth hormone on epiphyseal growth plates in zinc deficiency

This study was carried out on 18 albino rats. The control group, consisting of six rats, was fed a normal diet and tap water. The other rats were given a zinc-deficient diet and deionized water. Two weeks later the latter group was again divided into two into smaller groups. The first of these groups was given an given an additional 100 ppm of zinc acetate. From the fifteenth day onwards, the human growth hormone (Nanormon) was injected intra-peritoneally to each group at a dose of 80 micrograms/day for two weeks. At the end of the experiment, it was found that body weights were markedly increased in the control and zinc-added groups compared with the zinc-deficient rats. In the zinc-deficient group, serum zinc, hair zinc levels, alkaline phosphatase activity and serum protein levels were lower than those of the control and zinc-added groups. The zinc-deficient group had narrower tibial epiphyseal growth plates than those of the control group. The count of hypertrophied cells was also less in the zinc-deficient group. Based on these data, our conclusion was that the growth hormone becomes ineffective under conditions of zinc deficiency. This means that zinc deficiency has multidimensional effects on growth hormone activity.