Animals ; Bone and Bones ; metabolism ; Energy Metabolism ; physiology ; Humans ; Osteocalcin ; metabolism

The prevailing model of osteology is that bones constantly undergo a remodeling process, and that the differentiation and functions of osteoblasts are partially regulated by leptin through different central hypothalamic pathways. The finding that bone remodeling is regulated by leptin suggested possible endocrinal effects of bones on energy metabolism. Recently, a reciprocal relationship between bones and energy metabolism was determined whereby leptin influences osteoblast functions and, in turn, the osteoblast-derived protein osteocalcin influences energy metabolism. The metabolic effects of bones are caused by the release of osteocalcin into the circulation in an uncarboxylated form due to incomplete gamma-carboxylation. In this regard, the Esp gene encoding osteotesticular protein tyrosine phosphatase is particularly interesting because it may regulate gamma-carboxylation of osteocalcin. Novel metabolic roles of osteocalcin have been identified, including increased insulin secretion and sensitivity, increased energy expenditure, fat mass reduction, and mitochondrial proliferation and functional enhancement. To date, only a positive correlation between osteocalcin and energy metabolism in humans has been detected, leaving causal effects unresolved. Further research topics include: identification of the osteocalcin receptor; the nature of osteocalcin regulation in other pathways regulating metabolism; crosstalk between nutrition, osteocalcin, and energy metabolism; and potential applications in the treatment of metabolic diseases.
Bone Remodeling/physiology ; Bone and Bones/*metabolism ; *Energy Metabolism ; Humans ; Leptin/metabolism ; Osteocalcin/genetics/*metabolism

OBJECTIVETo study the mechanism of new bone formation and remodeling of distraction osteogenesis (DO) by analysis of the expression of osteopontin (OPN) and osteocalcin (OC).

METHODSRhesus were operated to reconstruct the animal model of cleft palate (CP). The CP was closed by DO in experimental group(n = 21). After consolidation of 1, 2, 4, 6, 8, 12, 24 weeks, every 3 animals were killed to collect the specimens, respectively. The OPN and OC and their mRNA were detected quantitatively by Real-time RT-PCR and ELISA, respectively. The animals in control group (n = 2) and sham group (n = 2) were used as control.

RESULTSThe mRNA expression of OPN increased since 2nd week of consolidation and reached the peak at 4th week (7.59 +/- 0.37). The mRNA expression of OC was up-regulated since 4th week, and reach the peak at 6th week (7.94 +/- 0.31). Then they decreased to about the level in sham group at 24th week (P > 0.05). The OPN and OC were highly expressed during 4 to 6 weeks of consolidation. During 8 to 12 weeks, they decreased like their mRNA expression.

CONCLUSIONThe intramembraneous new bone formation after DO can reconstruct the bone defect of CP. The new formed bone can be remodeled to be quite normal bone tissue.

Animals ; Cleft Palate ; metabolism ; surgery ; Macaca mulatta ; Osteocalcin ; metabolism ; Osteogenesis, Distraction ; Osteopontin ; metabolism

Animals ; Bone and Bones ; metabolism ; physiology ; Endocrine System ; metabolism ; physiology ; Female ; Humans ; Male ; Osteocalcin ; metabolism

OBJECTIVETo evaluate the biological effects of nano-hydroxyapatite/polyamide 66(nHA-PA66) on the growth and activity of osteoblast.

METHODSMTT assay was used to determine the growth of osteoblast, enzymatic measure was used to determine the activity of ALP and quantitative RT-PCR (QRT-PCR) to evaluate the changes of osteoclacin mRNA expression in osteoblasts treated by DMEM eluate of nHA-PA66.

RESULTSOsteoblasts of different test groups demonstrated relative proliferation rate ranging from 98% - 106% without dose-dependent effect. The ALP activity and osteocalcin mRNA expression were similar in test and control groups (P > 0.05).

CONCLUSIONnHA-PA66 has no negative effects on the osteoblast and its osteoblast-compatibility is proved.

Durapatite ; pharmacology ; Nylons ; pharmacology ; Osteoblasts ; drug effects ; Osteocalcin ; metabolism ; RNA, Messenger ; metabolism

Bone remodeling requires a large amount of energy, and is regulated by various hormones. Leptin, produced by adipocytes, is a well-known regulator of energy balance and is also involved in controlling bone mass through interaction with the central nervous system. Serotonin, downstream of leptin, is also emerging as a candidate for controlling energy balance and bone metabolism. Currently, bone is also considered to be an endocrine regulator of energy metabolism. Osteocalcin, secreted from osteoblasts, is known to be a key regulator of glucose and fat metabolism. In this review, we describe a novel concept that asserts that there exists a biological link between bone and energy metabolism, and we summarize what is currently known about the relationship between bone and energy metabolism.
Adipocytes ; Bone Remodeling ; Central Nervous System ; Energy Metabolism* ; Glucose ; Leptin ; Metabolism ; Neurotransmitter Agents ; Osteoblasts ; Osteocalcin ; Serotonin

OBJECTIVES: To investigate the patterns of biochemical bone markers, such as urinary deoxypyridinoline (DPD), N-telopeptide of type I collagen (NTX), and serum osteocalcin (OC), bone-specific alkaline pbosphatase (BSAP) in postmenopansal women with hormone replacement therapy (HRT). Materials and METHOD: From July 1997 to January 1998, total 239 postmenopausal women were emolled in the present study, and 198 healthy premenopausal women with regular menstruation were served as control. The postmenopausal women were pouped into the HRT group and the non-HRT group. The women in the HRT poup have received estrogen with continuous or cyclic progestin therapy far more tban 6 months. The biochemical bone markers of all women were assayed. Results were analysed with Students t-test. RESULTS: The urinary DPD of the non-HRT group was sigaificantly higher than both the HRT poup and the premenopausal group(5.51 +/- 2.47 vs. 3.36 +/- 1.02 and 4.01 +/- 3.86 nM/mM, p < 0.05, repectively). The urinary NTX of the non-HRT group was also higher in comparison to the HRT group and the premenopausal group(48.71 +/- 11.54 vs. 33.70 +/- 17.43 and 33.70 +/- 17.43 nM BCE/mmol, p < 0.05, repectively). However, there were no significant differences in the concentrations of serum BSAP and OC among the three poups. CONCLUSION: The urinary DPD and NTX were more sensitive indicators of bone metabolism tban serum BSAP and OC in postmenopausal women undergoing HRT.
Collagen Type I ; Estrogens ; Female ; Hormone Replacement Therapy* ; Humans ; Menstruation ; Metabolism ; Osteocalcin

BACKGROUND: In this study, we examined the influence of exercise loading characteristics on bone metabolic responses and bone morphology in the growth phase and adulthood. METHODS: Running exercise (RUN) and jumping exercise (JUM) were used for the exercise loading in 28-day-old male Wistar rats. Bone metabolism was measured by blood osteocalcin (OC) and tartrate-resistant acid phosphatase (TRACP) levels. For bone morphology, the maximum bone length, bone weight, and bone strength of the femur and tibia were measured. RESULTS: A pre- and post-exercise loading comparison in the growth phase showed significantly increased OC levels in the RUN and JUM groups and significantly decreased TRACP levels in the JUM group. On the other hand, a pre- and post-exercise loading comparison in adulthood showed significantly decreased TRACP levels in the RUN and JUM groups. Femur lengths were significantly shorter in the RUN and JUM groups than in the control (CON) group, while bone weight was significantly greater in the JUM group than in the CON group. CONCLUSIONS: Exercise loading activates OC levels in the growth phase and suppresses TRACP levels in adulthood. On the other hand, these results suggest that excessive exercise loading may suppress bone length.
Acid Phosphatase ; Femur ; Hand ; Humans ; Male ; Metabolism* ; Osteoblasts ; Osteocalcin ; Osteoclasts ; Osteogenesis* ; Rats, Wistar ; Running ; Tibia

PURPOSE: Abnormalities in calcium(Ca), vitamin D and bone mineral density (BMD) associated with antiepileptic drug(AED) are reported, but the results are inconsistent. In case of intractable epilepsy, poor growth and altered bone mineral metabolism may be prominent, possibly related to previous long-term use of multiple AED and poor activity. The aim of this study was to assess growth status, concentrations of calcium regulating hormones and BMD in children with intractable epilepsy. METHODS: Sixty-six intractable epilepsy patients aged 0.8 to 14.7 years(mean+/-D:4.6+/-.6 years) were included in the study. Height and weight were measured and then height SDS and weight SDS were calculated. Serum Ca, i-Ca, P, Mg, Zinc, osteocalcin, intact-PTH, 25-OHD, 1,25(OH)2D were measured. BMD of the lumbar spine was measured by dual energy X-ray absorption. RESULTS: Most of the patients showed normal height SDS and weight SDS. Percentage of severe short stature(height SDS <-2) was 1.5% and tall stature(height SDS >2) was 4.5%. Percentage of severe thin(weight SDS <-2) was 1.5% and obesity(weight SDS >2) was 6%. Duration of AED was not related to height SDS or weight SDS. Etiology of epilepsy and physical activity were not related to height SDS and weight SDS. Most of them had normal Ca, iCa, P, Mg, Zinc, intact-PTH, osteocalcin, 25-OHD and 1,25(OH)2D concentrations. BMD was not related to the levels of Ca, i-Ca, P, Mg, intact-PTH, osteocalcin, 25-OHD, 1,25(OH)2D. BMD was not related to the duration of AED. BMD positively correlated with age(r=0.75, P>0.01) and body weight(r=0.72, P<0.01). CONCLUSION: Most of the children with intractable epilepsy, who regularly visits epilepsy clinic, showed normal growth and normal bone mineral metabolism, but careful monitoring about growth and bone mineral metabolism is needed.
Absorption ; Bone Density* ; Calcium* ; Child* ; Epilepsy* ; Humans ; Metabolism ; Motor Activity ; Osteocalcin ; Spine ; Vitamin D ; Zinc

PURPOSE: The purpose of this study was to investigate the effects of low energy-ultraviolet B (UVB) irradiation on bone metabolism and turnover in mice. MATERIALS AND METHODS: Five-week old C57BL/6 mice were randomly allocated into two groups. Control group (n=35) was not exposed to UVB and experimental group (n=35) was exposed to low energy-UVB for 30 min a day during 7 days. Serological and radiological examination was performed at 0, 1, 2, 4, 8 week(s) of each group (n=7). RESULTS: Analysis of biochemical bone markers revealed that alkaline phosphatase (ALP) was detected higher in the UVB group compared to control group. Serum level of osteocalcin was higher in UVB group at 1st week after UVB irradiation (p=0.031). The mean value of Vitamin D was significantly higher in UVB group than control group (p=0.032). Bone mineral density (BMD) from both 5th lumbar spine (p=0.124) and femur (p=0.862) showed higher in UVB group than control group from two weeks after irradiation, but they were not statistically significant. CONCLUSION: Our study with radiological bone mineral density and serological tests for biochemical bone turnover markers revealed that ultraviolet irradiation contributed positive effect on bone formation.
Alkaline Phosphatase ; Animals ; Bone Density ; Femur ; Metabolism* ; Mice* ; Osteocalcin ; Osteogenesis ; Serologic Tests ; Spine ; Vitamin D