Effect of parathyroid hormone on hypogonadism induced bone loss of proximal femur of orchiectomized rat

• Published in: World journal of urology Vol. 29; no. 4; pp. 529 - 534
• Main Authors: Tezval, M., Serferaz, G., Rack, T., Kolios, L., Sehmisch, S., Schmelz, U., Tezval, H., Stuermer, K. M., Stuermer, E. K.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-08-2011; Springer; Springer Nature B.V
• Subjects: Animals; Biological and medical sciences; Biomechanical Phenomena - drug effects; Biomechanical Phenomena - physiology; Body Weight - drug effects; Body Weight - physiology; Bone (cortical); Bone Density - drug effects; Bone Density - physiology; Bone loss; Bone strength; Disease Models, Animal; Diseases of the osteoarticular system; Dose-Response Relationship, Drug; Femur; Femur - drug effects; Femur - pathology; Femur - physiopathology; Fluorescence; Geriatrics; Hypogonadism; Hypogonadism - complications; Immunofluorescence; Injections, Subcutaneous; Male; Medical sciences; Medicine; Medicine & Public Health; Minerals; Nephrology; Nephrology. Urinary tract diseases; Oncology; Orchiectomy; Original; Original Article; Osteoporosis; Osteoporosis - drug therapy; Osteoporosis - etiology; Osteoporosis - physiopathology; Osteoporosis. Osteomalacia. Paget disease; Parathyroid hormone; Parathyroid Hormone - administration & dosage; Parathyroid Hormone - pharmacology; Parathyroid Hormone - therapeutic use; Rats; Rats, Sprague-Dawley; Urology; Osteoporosis; Parathyroid hormone; Hypogonadism; Trochanteric region; Proximal; Femur; Nephrology; Rat; Peptide hormone; Diseases of the osteoarticular system; Rodentia; Urology; Genital diseases; Vertebrata; Mammalia; Animal; Osteopenia
• ISSN: 0724-4983; 1433-8726
• DOI: 10.1007/s00345-011-0652-9

Purpose
Management of hypogonadism-induced osteoporosis in elderly men is still a challenge. We investigated the short-term effects of parathyroid hormone (PTH) treatments on strength, micro-architecture, and mineral density of trochanteric region of orchiectomized rat femur.
Methods
Eight-month-old male Sprague–Dawley rats (
n
 = 44) were divided into two groups: (1) orchiectomized (ORX) and (2) sham group. Twelve weeks after orchiectomy, half of the orchiectomized animals were treated with daily subcutaneously injected PTH (0.040 mg/kg/BW) (ORX-PTH) for 5 weeks. The other half remained untreated (ORX). The sham-operated group was divided and treated in the same way (sham, sham-PTH). After 5 weeks, both femurs were excised for biomechanical and histomorphometric analysis, trabecular measurements, mineral content assessment, and immunofluorescence analysis.
Results
The femoral trochanteric strength after PTH treatment was enhanced in the breaking test (ORX-F
max
 = 158.7 N vs. ORX + PTH-F
max
 = 202 N). Stiffness of treated ORX animals reached nearly the levels observed in untreated sham rats. PTH therapy improved the trabecular connectivity, width, and area (ORX-Tb.Ar = 47.79% vs. ORX + PTH-Tb.Ar = 68.47%,
P
 < 0.05) in the proximal femur. The treated rats showed significantly improved mineral content in ashed femurs (ORX-mineral content = 43.73% vs. ORX + PTH-mineral content = 49.49%) when compared to the untreated animals. A comparison of widths of fluorescence bands in cortical bone of the subtrochanteric cross-sections showed a significant increase in oppositions after the PTH therapy.
Conclusions
Our finding supports the hypothesis that PTH therapy seems to be a rational therapy in patients with hypogonadism induced bone loss and improves the bone strength of trochanteric region of rat femur.