Separate and combined effects of growth hormone and parathyroid hormone on cortical bone osteopenia in ovariectomized aged rats

2001 ◽  
Vol 13 (4) ◽  
pp. 282-292 ◽  
Author(s):  
M. J. Banu ◽  
P. B. Orhii ◽  
L. Wang ◽  
D. N. Kalu
Keyword(s):  
Growth Hormone ◽  
Parathyroid Hormone ◽  
Cortical Bone ◽  
Combined Effects ◽  
Aged Rats

The influence of growth hormone on cancellous and cortical bone of the vertebral body in aged rats

2009 ◽  
Vol 11 (8) ◽  
pp. 1094-1102 ◽  
Author(s):  
Troels T. Andreassen ◽  
Flemming Melsen ◽  
Hans Oxlund
Keyword(s):  
Growth Hormone ◽  
Cortical Bone ◽  
Vertebral Body ◽  
Aged Rats

Growth hormone stimulates bone formation and strength of cortical bone in aged rats

2009 ◽  
Vol 10 (7) ◽  
pp. 1057-1067 ◽  
Author(s):  
Troels T. Andreassen ◽  
Peter H. Jørgensen ◽  
Hans Oxlund ◽  
Allan Flyvbjerg ◽  
Hans Ørskov
Keyword(s):  
Growth Hormone ◽  
Bone Formation ◽  
Cortical Bone ◽  
Aged Rats

Human parathyroid hormone(1–34) increases bone formation and strength of cortical bone in aged rats

1994 ◽  
Vol 130 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Charlotte Ejersted ◽  
Troels T Andreassen ◽  
Magnus HL Nilsson ◽  
Hans Oxlund
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Cortical Bone ◽  
Formation Rate ◽  
The Body ◽  
Male Rats ◽  
Double Labelling ◽  
Aged Rats ◽  
Human Parathyroid Hormone ◽  
Bone Formation Rate

Ejersted C, Andreassen TT, Nilsson MHL, Oxlund H. Human parathyroid hormone(1–34) increases bone formation and strength of cortical bone in aged rats. Eur J Endocrinol 1994;130:201–7. ISSN 0804–4643 The effect of parathyroid hormone (PTH(1–34)) on mid-diaphyseal femoral cortical bone was studied in 2-year-old male rats. The rats were treated with daily injections of 1 5 nmol/kg PTH(1–34) or vehicle for 56 days, and labelled with tetracycline and calcein on day 15 and day 40, respectively. The PTH(1–34) treatment did not affect the body weights or the lengths of the femora. Fluorescence microscopy showed large intracortical cavities in the old vehicle-treated rats. After PTH treatment, double labelling and new bone formation filling in these cavities were found. Furthermore, an increased bone formation rate was observed both at the periosteum and at the endosteum. This resulted in an increase in the cross-sectional area and a decrease in the medullary area. Three-point bending analysis revealed an increase in ultimate load, ultimate stiffness, energy absorption and ultimate stress after the PTH(1–34) treatment. No differences were found between the groups regarding the hydroxyproline concentration or apparent and real densities. The ash concentration was, however, slightly reduced after PTH(1–34) treatment. The PTH(1–34) treatment of old rats induced the formation of bone both from the periosteum and endosteum, with a pronounced filling in of intracortical cavities, and, furthermore, a marked increase in the biomechanical competence of the cortical bone. Charlotte Ejersted, Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, DK-8000 Aarhus C. Denmark

scholarly journals Impairment of Host Liver Repopulation by Transplanted Hepatocytes in Aged Rats and the Release by Short-Term Growth Hormone Treatment

2017 ◽  
Vol 187 (3) ◽  
pp. 553-569 ◽  
Author(s):  
Peggy Stock ◽  
Maximilian Bielohuby ◽  
Martin S. Staege ◽  
Mei-Ju Hsu ◽  
Martin Bidlingmaier ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Treatment ◽  
Hormone Treatment ◽  
Aged Rats ◽  
Host Liver ◽  
Short Term ◽  
Liver Repopulation

Regulation of parathyroid hormone secretion by plasma calcium in aging rats

1991 ◽  
Vol 260 (2) ◽  
pp. E220-E225 ◽  
Author(s):  
J. Fox
Keyword(s):  
Parathyroid Hormone ◽  
Hormone Secretion ◽  
Fold Increase ◽  
Male Rats ◽  
Aged Rats ◽  
Adult Rats ◽  
Dihydroxyvitamin D3 ◽  
Set Point ◽  
Skeletal Resistance ◽  
Immunoreactive Parathyroid Hormone

Plasma immunoreactive parathyroid hormone (irPTH) levels increase with aging. This study determined 1) whether NH2-terminal irPTH secretory responses to induced hypocalcemia differ between adult (6-mo-old) and aged (24- to 26-mo-old) male rats and 2) whether a higher set point for irPTH release by Ca is responsible for the elevated irPTH levels with aging. Basal irPTH levels were 68% higher and 1,25-dihydroxyvitamin D3 levels were 44% lower in aged rats. An acutely induced, constant hypocalcemic stimulus [0.32 mM decrement in ionized Ca (Ca2+) for 2 h] was developed in catheterized conscious adult and aged rats by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) infusion using the Ca clamp technique. The initial irPTH secretory response to acute hypocalcemia (5-10 min) was reduced in aged rats (1.9- vs. 3.1-fold increase), suggesting reduced hormone stores. However, higher sustained irPTH levels (30 min to 2 h) were maintained in aged rats, indicating increased irPTH synthesis and release. The EGTA infusion rate necessary to maintain constant hypocalcemia was less in aged rats, suggesting skeletal resistance to PTH. Slow EGTA and Ca infusions were used to determine irPTH secretion at plasma Ca2+ levels from 0.7 to 1.5 mM. In aged rats, irPTH levels were higher at all Ca2+ concentrations, but the set point for irPTH release by Ca2+ was the same as in adult rats. Thus the elevated irPTH secretion in aged rats is not caused by a change in the set point for irPTH release but does result in decreased irPTH stores.

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