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

Abstract

PurposeManagement 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.MethodsEight-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.ResultsThe femoral trochanteric strength after PTH treatment was enhanced in the breaking test (ORX-Fmax = 158.7 N vs. ORX + PTH-Fmax = 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.ConclusionsOur 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.

Efficiency of 48h vs. 24h Injection of Parathyroid Hormone for Amelioration of Osteopenic Spine Properties in Male Rats

“…Recent study showed that PTH administration improved bone healing in both healthy and ovariectomy-induced osteopenic rats regardless of application frequency (7, 5 times per week or every other day) [14]. Part of the present study has been published previously [15,16]. It was shown, that in aged males the effect of PTH on bone healing was less when it was applied with less frequency (every day vs. every other day) [15].…”

“…It was shown, that in aged males the effect of PTH on bone healing was less when it was applied with less frequency (every day vs. every other day) [15]. The proximal femur responded to PTH treatments positively showing improved biomechanical properties, mineral content and trabecular bone parameters [16]. Thus, PTH improved tibia healing and reversed structural impairment in femur in male rats.…”

Histological study of the femur and the lumbar vertebrae in ovariectomized adult albino rats following administration of collagen hydrosylate

“…The ovariectomized (OVX) rat is the most appropriate experimental model for postmenopausal bone loss that faithfully reproduces the changes observed in human subjects and has the added benefit that the effects are detectable only a few months after gonadectomy [14,22]. There are many similarities between the human and rat femur, both at the microstructural and macrostructural levels [23,24]. There are many similarities between the human and rat femur, both at the microstructural and macrostructural levels [23,24].…”

“…The femur is one of the most important skeletal sites in postmenopausal osteoporosis. For these reasons, this skeletal site has gained special meaning and great importance in osteoporosis studies [24]. For these reasons, this skeletal site has gained special meaning and great importance in osteoporosis studies [24].…”

Phospholipase C signaling activated by parathyroid hormone mediates the rapid osteoclastogenesis in the fracture healing of orchiectomized mice

“…Previous studies showed that both the osteoporosis-related morbidity and mortality in men actually were higher than those in women in later life [ 1 , 2 ]. The increased risk of fractures is closely associated with the decline of testosterone production, which causes a high turnover bone loss from cancellous bone sites [ 1 , 3 , 4 ].…”