Effects of Growth Hormone on Bone Modeling and Remodeling in Hypophysectomized Young Female Rats: A Bone Histomorphometric Study by Lysette Iglesias MD
Abstract: Growth hormone (GH) deficiency causes decreased bone mineral density and osteoporosis, predisposing to fractures. We investigated the mechanism of action of GH on bone modeling and remodeling in hypophysectomized (HX) female rats. Thirty female Sprague–Dawley rats at age 2 months were divided into three groups with 10 rats each: control (CON) group, HX group, and HX GH (3 mg/kg daily SC) group, for a 4-week study. Hypophysectomy resulted in cessation of bone growth and decrease in cancellous bone mass. Periosteal bone formation decreased and bone turnover rate of endocortical and trabecular surfaces increased as compared to the CON group. GH administration for 4 weeks restored weight gain and bone growth and mitigated decrease in bone density after hypophysectomy.