Beneficial Effects of Combined Administration of Alendronate and Alfacalcidol on Cancellous Bone Mass of the Tibia in Orchidectomized Rats: A Bone Histomorphometry Study

Abstract

SummaryThe purpose of the present study was to examine the effects of combined administration of alendronate (ALN) and alfacalcidol (ALF) on the cancellous and cortical bone mass of the tibia in orchidectomized rats. Fifty male Sprague-Dawley rats, 3 mo of age, were randomized by the stratified weight method into five groups: age-matched control, orchidectomy, and orchidectomy with administration of ALN (2.5 g/kg, s.c., 5 times a week), ALF (0.05 g/kg, p.o., 5 times a week), or ALN ϩ ALF. The total experimental period was 12 wk. Orchidectomy reduced the cancellous bone mass of the proximal tibial metaphysis and maturation-related cortical bone gain of the tibial diaphysis as a result of increased trabecular bone resorption and decreased periosteal bone formation and also increased endocortical bone erosion and formation. ALN suppressed trabecular bone resorption and endocortical bone erosion and formation and increased periosteal bone formation, while ALF increased the number of osteoblasts and suppressed trabecular bone resorption and markedly increased periosteal and endocortical bone formation. Thus, both ALN and ALF prevented the orchidectomy-induced reduction in the cancellous bone mass and maturation-related cortical bone gain. Combined administration of ALN and ALF increased the cancellous bone mass as compared with the values observed in age-matched controls by causing more marked suppression of trabecular bone resorption. The present study showed the beneficial effects of combined administration of ALN and ALF on the cancellous bone mass of the tibia in orchidectomized rats. Key Words orchidectomy, osteopenia, alendronate, alfacalcidol, rat Testosterone is important for skeletal growth during the period of linear growth in males, and is also responsible for maintenance of the skeletal mass in the later stage of life ( 1-3 ). Testosterone deficiency, caused by orchidectomy (ORX), has been reported to induce highturnover cancellous osteopenia and cortical osteopenia with decreased periosteal bone formation in rats ( 4 , 5 ). We clarified, based on the findings in bone specimens obtained from 3-mo-old male Sprague-Dawley (SD) rats, that ORX induced cancellous osteopenia of the proximal tibial metaphysis as a result of increased bone resorption, and reduced maturation-related gain in the cortical bone mass of the tibial diaphysis as a result of decreased periosteal bone formation ( 6 ).Bone growth, bone modeling, and Basic Multi-Cellular Unit (BMU)-based bone remodeling differ between the cortical and cancellous bones. Typically, bone growth and modeling drifts are predominant in cortical bone and can increase the bone mass, whereas bone remodeling occurs primarily in the cancellous bone, and can either conserve or remove bone in contact with the marrow in rats ( 7 ). Bone modeling may add bone mass but can never result in a reduction in the bone mass, whereas bone remodeling usually results in a zero or negative balance of the bone mass. Thus, it was suggested that ORX in 3-mo-old male SD rats resulted in ...

Protective actions of green tea polyphenols and alfacalcidol on bone microstructure in female rats with chronic inflammation

“…The findings show that LPS-induced chronic inflammation (the L group) produced a detrimental effect on bone mass and microarchitecture, in terms of a decrease in trabecular volume and thickness of femur and proximal tibia, and an increase in Tb.Sp in proximal tibia, compared to a placebo-treated group (the P group). Such a detrimental effect on bone mass and microarchitecture by LPS agrees with a previous study as measured by μCT [20]. Compared to those receiving GTP (the LG group) or 1-α-OH-vitamin D 3 alone (the LD group), the rats receiving both treatments (the LGD group) for 12 weeks had a synergistic effect with the highest values for bone mass of femur (Fig.…”

“…The rats in the LD group were orally given 1-α-OH-vitamin D 3 at 0.05 μg/kg body weight, 5 times per week. Such a dosage of 1-α-OH-vitamin D 3 has shown a decrease in trabecular bone resorption, but an increase in the number osteoblasts, and periosteal and endocortical bone formation of rats [20]. The rats in the LG group were provided with GTP supplementation (0.5%, w/v) in drinking water daily to mimic human consumption of green tea of 4 cups a day based on our previous human [21] and animal studies [2,22].…”

Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats

“…The rats in the LD group were orally administrated with 1- α -OH-vitamin D 3 at 0.05 μg/kg body weight, five times per week. The use of 1- α -OH-vitamin D 3 is based on a previous study that 1- α -OH-vitamin D 3 (0.5 μg/kg, five times a week) increased the number of osteoblasts and suppressed trabecular bone resorption and markedly increased periosteal and endocortical bone formation [39]. The rats in the LGD group were given both GTP and 1- α -OH-vitamin D 3 .…”

The effect of caponization on tibia bone histomorphometric properties of crossbred roosters

“…The histomorphometric studies of the midshaft part of long bones are rarely the subject of the research. Therefore, information on the effect of castration on histomorphometric parameters of the compact bone is limited and concerns only mammals 34 , 35 , 37 . Noteworthy, that our study is the first to analyze the effect of caponization on the midshaft tibia bone microstructure.…”