Synergistic Effect of Parathyroid Hormone and Growth Hormone on Trabecular and Cortical Bone Formation in Hypophysectomized Rats

Abstract

Background/Aims: Growth hormone (GH) deficiency in pediatric patients results in short stature and osteopenia. We postulated that the GH and parathyroid hormone (PTH) combination would result in improvement in bone growth and bone formation. Methods: Forty hypophysectomized female rats at age 8 weeks were divided into hypophysectomy (HX), HX + PTH (62.5 µg/kg, s.c. daily), HX + GH (3.33 mg/kg, s.c. daily), and HX + PTH + GH for a 4-week study. Results: GH increased body weight, bone growth, bone mineral content (BMC) and bone mineral density (BMD), whereas PTH increased BMC and BMD without a significant effect on bone size. GH increased both periosteal and endocortical bone formation and cortical size, while PTH increased only endocortical bone formation. GH mitigated the trabecular bone loss by increasing bone formation, while PTH increased bone mass by increasing bone formation and suppressing osteoclast number per bone area. The result of combined intervention shows an increase in trabecular, periosteal and endocortical bone formation and suppression of bone resorption resulting in a synergistic effect on increasing trabecular and cortical bone volume and BMD. Conclusion: The combination treatment of PTH and GH increases bone growth, bone formation, decreases bone resorption and has a synergistic effect on increasing bone density and bone mass.

DMP‐1 ‐mediated Ghr gene recombination compromises skeletal development and impairs skeletal response to intermittent PTH

“…In a study in hypophysectomized (HX) rats, treatment with the combination of PTH and GH resulted in substantial bone deposition at both the periosteal and endocortical surfaces, leading to increased BMD (55). GH had anabolic effects on the periosteal surface of the cortical shell and enhanced bone formation without suppressing bone resorption, whereas PTH acted mainly on the endosteal surfaces and stimulated trabecular bone formation and cortical bone thickening.…”

Correction: Differential effects of growth hormone and alfa calcidol on trabecular and cortical bones in hypophysectomized rats

“…In addition, the article failed to acknowledge the fact that it was part of a larger project, and that the other part of this project examined the synergistic effect of PTH and GH on bone formation in hypophysectomized rats. 1 Furthermore, a number of minor omissions/errors were made throughout the article. The methods section omitted that the HX rats were 8 weeks of age at the time they were assigned into groups.…”

“…The correct unit is '#/mm'. The footnotes of tables 1-3 also omitted that part of the data for the 'INTACT', 'HX', and 'HX+GH' groups had also been used in the study by Guevarra et al, 1 which was under review at the time.…”

Bone metabolism in patients with mucopolysaccharidosis type II

“…Similarly, although hematopoietic stem-cell transplantation (HSCT) leads to some positive changes, it does not greatly reduce the skeletal abnormalities. Another alternative might be growth hormone (GH), which improves osteopenia in pediatric patients with growth hormone deficiency [28]. It is not known, however, whether it also improves the osteopenia in MPS patients.…”

“…It is not known, however, whether it also improves the osteopenia in MPS patients. In a GH deficient rat model it was demonstrated that GH administration increases periosteal and endocortical bone formation and mitigates trabecular bone loss by increasing bone formation [28]. Since trabecular bone loss has been demonstrated in most MPS animal models, it may be worthwhile to investigate the effect of GH dosing in MPS patients [12].…”