OBJECTIVETo investigate the influence of parathyroid hormone and estrogen on alveolar bone metabolism of castrated female rats.

METHODSSixty-six female Wistar rats which were healthy and 4 months old were divided into two groups, with group SHAM (n = 18) and group ovariectomy (OVX) (n = 48). After 8 weeks of ovariectomy, the osteoporosis model was confirmed by examing 8 ovariectomized and sham-operated rats. The rest 10 rats in group SHAM were the control group (group A). The rest 40 rats in group OVX were divided into ovariectomized group (group B), ovariectomized and treated with estrogen (group C), ovariectomized and treated with parathyroid hormone (group D), ovariectomized and treated with estrogen and parathyroid hormone (group E) at random with 10 in each group. Group A and B injected physiological saline (1 mL x kg(-1)), group C injected estradiol benzoate (10 microg x kg(-1)), group D injected parathyroid hormone (20 microg x kg(-1)), group E injected parathyroid hormone (20 microg x kg(-1)) and estradiol benzoate (10 microg x kg(-1)). The intraperitoneal injection were maken every other day to rats in each group, which continued for 8 weeks. The bone mineral density (BMD), bone histomorphology and serum Ca, P, alkaline phosphatase (ALP) were measured after therapy.

RESULTSAfter 8 weeks of ovariectomy, the lumbar BMD of ovariectomized rats were significantly declined compared with those of the sham-operated rats (P < 0.05). Eight weeks later after the drug use, the BMD, %Tb.Ar, Tb.Th, Tb.N in group C, D, E were slightly elevated compared to group B, especially the group E (P < 0.05). Serum calcium and phosphorus values did not change significantly (P > 0.05). ALP values in group B was significantly higher than that in group A (P < 0.05).

CONCLUSIONIntermittent application of parathyroid hormone in small doses can increase alveolar BMD of castration rats and improve their bone structure. And it can have synergy effects on the treatment of osteoporosis if it is used combining with estrogen.

Alkaline Phosphatase ; Animals ; Bone Density ; Estradiol ; analogs & derivatives ; Estrogens ; Female ; Osteoporosis ; Ovariectomy ; Parathyroid Hormone ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar

OBJECTIVETo assess the effect of intermittent subcutaneous injections of signal-selective parathyroid hormone (PTH) peptide analog on fracture healing in orchiectomized mouse models.

METHODSThirty-six 7-week-old C57/BL male mice were orchiectomized and injected with hPTH(1-34), the signal-selective PTH peptide analog [Gly(1), Arg(19)]hPTH (1-34), or an identical volume of vehicle 1 week after induction of femoral fracture. At 14 and 28 days after the operation, the mice were sacrificed for measurement of bone mineral density (BMD) and bone mineral content (BMC) of the callus using by dual energy X-ray absorptiometry. The bone healing was evaluated by radiography, biomechanical testing, micro-computed tomography (Micro-CT) and histological examination.

RESULTSAt 14 days after the operation, BMD in PTH peptide analog group was significantly increased (P<0.05). The mouse models treated with the PTH peptide analog showed significantly lower ultimate bending force and bending rigidity than those with hPTH(1-34) treatment. X-ray and Micro-CT scanning showed that callus transformation and remodeling was better in PTH peptide analog group than in the vehicle control group but poorer than in hPTH(1-34) group.

CONCLUSIONThe signaling-selective PTH peptide analog G1, R19 (1-28) can accelerate fracture healing in orchiectomized mouse models, in which process cAMP/PKA pathway plays an important role.

Animals ; Bone Density ; Fracture Healing ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Orchiectomy ; Parathyroid Hormone ; analogs & derivatives ; pharmacology ; Signal Transduction

BACKGROUND: The objective of this study was to evaluate the role of proteases on the degradation of parathyroid hormone (PTH) in blood samples. METHODS: Protease inhibitors with specificity against serine proteases (aprotinin), cysteine proteases (E-64), serine and cysteine proteases (leupeptin), metalloproteases (EDTA), or a protease inhibitor cocktail with a broad spectrum of inhibitory activity were added to blood samples. After storage at room temperature (0-48 hr), PTH levels were measured. RESULTS: PTH levels in samples with the protease inhibitor cocktail did not change significantly after 48 hr of storage at room temperature, but the average PTH levels decreased by 40.7% and 20.1%, in samples stored at room temperature and stored at 4degrees C without protease inhibitors, respectively. PTH levels in samples with leupeptin were stable for up to 24 hr. After 48 hr, the mean PTH levels decreased by 17.1%, 16.0%, 26.2%, and 32.1%, with 500 KIU/mL aprotinin, 100 micro mol/L leupeptin, 10 micro mol/L E-64, and 10 micro mol/L EDTA, respectively, in the samples stored at room temperature. CONCLUSIONS: The decrease in PTH levels in blood samples seemed to be due to the degradation of PTH by proteases. Various proteases, including especially serine proteases, would act together to degrade PTH in blood specimen. The PTH degradation may be inhibited in blood specimen with protease inhibitor cocktail.
Aprotinin/pharmacology ; Blood Specimen Collection ; Edetic Acid/pharmacology ; Female ; Humans ; Leucine/analogs & derivatives/pharmacology ; Leupeptins/pharmacology ; Male ; Parathyroid Hormone/*blood/metabolism ; Protease Inhibitors/*pharmacology ; Time Factors

BACKGROUNDRecombinant human parathyroid hormone (1-34) (rhPTH (1-34)) is the first agent in a unique class of anabolic therapies acting on the skeleton. The efficacy and safety of long-term administration of rhPTH (1-34) in Chinese postmenopausal women had not been evaluated. This study compared the clinical efficacy and safety of rhPTH (1-34) with elcatonin for treating postmenopausal women with osteoporosis in 11 urban areas of China.

METHODSA total of 453 postmenopausal women with osteoporosis were enrolled in an 18-month, multi-center, randomized, controlled study. They were randomized to receive either rhPTH (1-34) 20 µg (200 U) daily for 18 months, or elcatonin 20 U weekly for 12 months. Lumbar spine (L1-4) and femoral neck bone mineral density (BMD), fracture rate, back pain as well as biochemical markers of bone turnover were measured. Adverse events were recorded.

RESULTSrhPTH (1-34) increased lumbar BMD significantly more than did elcatonin after 6, 12, and 18 months of treatment (4.3% vs. 1.9%, 6.8% vs. 2.7%, 9.5% vs. 2.9%, P < 0.01). There was only a small but significant increase of femoral neck BMD after 18 months (2.6%, P < 0.01) in rhPTH groups. There were larger increases in bone turnover markers in the rhPTH (1-34) group than those in the elcatonin group after 6, 12, and 18 months (serum bone-specific alkaline phosphatase (BSAP) 93.7% vs. -3.6%; 117.8% vs. -4.1%; 49.2% vs. -5.8%, P < 0.01; urinary C-telopeptide/creatinine (CTX/Cr) 250.0% vs. -29.5%; 330.0% vs. -41.4%, 273.0% vs. -10.6%, P < 0.01). rhPTH (1-34) showed similar effect of pain relief as elcatonin. The incidence of clinical fractures was 5.36% (6/112) in elcatonin group and 3.2% (11/341) in rhPTH (1-34) group (P = 0.303). Both treatments were well tolerated. Hypercaluria (9.4%) and hypercalcemia (7.0%) in rhPTH (1-34) group were transient and caused no clinical symptoms. Pruritus (8.2% vs. 2.7%, P = 0.044) and redness of injection site (4.4% vs. 0, P = 0.024) were more frequent in rhPTH (1-34). Nausea/vomiting (16.1% vs. 6.2%, P = 0.001) and hot flushes (7.1% vs. 0.6%, P < 0.001) were more common in elcatonin group.

CONCLUSIONSrhPTH (1-34) was associated with greater increases in lumbar spine BMD and bone formation markers. It could increase femoral BMD after 18 months of treatment. rhPTH could improve back pain effectively. The results of the present study indicate that rhPTH (1-34) is an effective, safe agent in treating Chinese postmenopausal women with osteoporosis.

Aged ; Bone Density ; drug effects ; Calcitonin ; analogs & derivatives ; therapeutic use ; China ; Female ; Humans ; Middle Aged ; Osteoporosis, Postmenopausal ; drug therapy ; Parathyroid Hormone ; therapeutic use ; Treatment Outcome

BACKGROUNDRecombinant human parathyroid hormone (1-34) (rhPTH (1-34)) given by injection is a new seventh class drug of biological products, which is prepared by adopting gene recombination technique. rhPTH (1-34) is mainly used to treat osteoporosis, especially for postmenopausal women. This study compared the clinical efficacy and safety of rhPTH (1-34) with elcatonin for treating postmenopausal women with osteoporosis in 11 urban areas of China.

METHODSTwo hundred and five women with osteoporosis were enrolled in a 6-month, multicenter, randomized, controlled study. They were randomized to receive either rhPTH (1-34) 20 microg (200 U) daily or elcatonin 20 U weekly. Lumbar spine (L1-4) and femoral neck bone mineral density (BMD), as well as biochemical markers of bone turnover were measured. Adverse events were recorded.

RESULTSrhPTH (1-34) increased lumbar BMD significantly more than did elcatonin at 3 months and 6 months (2.38% vs 0.59%, P < 0.05; 5.51% vs 1.55%, P < 0.01), but there were no significant increases of BMD in these two groups at femoral neck. There were larger mean increases in bone markers in the rhPTH (1-34) group than in the elcatonin group at 3 months and 6 months (serum bone-specific alkaline phosphatase (BSAP) 36.79% vs 0.31%; 92.42% vs -0.17%; urinary N-telopeptide/creatinine (NTX/Cr) 48.91% vs -5.32%; 68.82% vs -10.86%). Both treatments were well tolerated and there were no significant differences detected between the two groups in the proportion of any adverse events and any serious adverse events (67.0% vs 59.0%; 0 vs 0).

CONCLUSIONSrhPTH (1-34) has more positive effects on bone formation, as shown by the larger increments of lumbar BMD and bone formation markers, than elcatonin, with only mild adverse events and no significant change in the liver, kidney or hematological indices.

Aged ; Calcitonin ; analogs & derivatives ; pharmacology ; therapeutic use ; Female ; Humans ; Middle Aged ; Osteogenesis ; drug effects ; Osteoporosis, Postmenopausal ; drug therapy ; Parathyroid Hormone ; pharmacology ; therapeutic use ; Recombinant Proteins ; pharmacology ; therapeutic use

Familial benign hypocalciuric hypercalcemia (FBHH) is an autosomal dominant trait with high penetrance, clinically manifestating a relatively benign, lifelong, persistent hypercalcemia and hypocalciuria without hypercalcemic related complications. The calcium-sensing receptor (CaSR) plays an important role in the regulation of PTH secretion and calcium metabolism. Here we present a family with FBHH of an autosomal dominant inheritance. A heterozygous mutation of E297K (GAG -> AAG, exon 4) of CaSR gene was found in 3 family members. To our knowledge, it is the first confirmed case of FBHH with CaSR gene mutation in Korea.
Sequence Analysis, DNA ; Receptors, Calcium-Sensing/*genetics ; Pedigree ; Parathyroid Hormone/analogs & derivatives/genetics/metabolism ; *Mutation ; Metabolism, Inborn Errors/*genetics ; Male ; Korea ; Hypercalcemia/*genetics ; Humans ; Heterozygote ; Genes, Dominant ; Female ; Family Health ; Exons ; DNA Restriction Enzymes/metabolism ; DNA/metabolism ; Adult

There is controversy regarding definition of vitamin D inadequacy. We analyzed threshold 25-hydroxyvitamin D (25[OH]D) below which intact parathyroid hormone (iPTH) increases, and examined age- and sex-specific changes of 25(OH)D and iPTH, and association of 25(OH)D and iPTH with bone mineral density (BMD) in elderly Koreans. Anthropometric parameters, serum 25(OH)D and iPTH, lumbar spine and femur BMD by dual-energy radiography absorptiometry (DXA) were measured in 441 men and 598 postmenopausal women. iPTH increased below serum 25(OH) of 36.7 ng/mL in men, but failed to reach plateau in women. Femur neck BMD above and below threshold differed when threshold 25(OH)D concentrations were set at 15-27.5 ng/mL in men, and 12.5-20 ng/mL in postmenopausal women. Vitamin D-inadequate individuals older than 75 yr had higher iPTH than those aged < or = 65 yr. In winter, age-associated iPTH increase in women was steeper than in summer. In conclusion, vitamin D inadequacy threshold cannot be estimated based on iPTH alone, and but other factors concerning bone health should also be considered. Older people seemingly need higher 25(OH)D levels to offset age-associated hyperparathyroidism. Elderly vitamin D-inadequate women in the winter are most vulnerable to age-associated hyperparathyroidism.
Absorptiometry, Photon ; Age Factors ; Aged ; *Bone Density ; Female ; Femur/anatomy & histology ; Humans ; Hyperparathyroidism/diagnosis/etiology ; Lumbosacral Region/anatomy & histology ; Male ; Middle Aged ; Parathyroid Hormone/*blood ; Postmenopause ; Republic of Korea ; Seasons ; Sex Factors ; Vitamin D/*analogs & derivatives/blood

PURPOSE: To find out the possible role of 1,25(OH)2 vitamin D3 [1,25(OH)2D3] and parathyroid hormone (PTH) as intrinsic factors in urinary calcium stone formers (SFs), we investigated their relationship with serum and urinary biochemical parameters. MATERIALS AND METHODS: A total of 326 calcium SFs (male: 204, female: 122) were enrolled and underwent outpatient metabolic evaluations including 1,25(OH)2D3 and PTH as well as serum and 24-hour urinary biochemical parameters. As control, 163 age- and sex-matched (2:1) individuals (non-SFs) who have never urinary stone episode were included. RESULTS: 1,25(OH)2D3 level was positively correlated with urinary calcium excretion (r=0.347, p<0.001). The hypercalciuric group and recurrent SFs had higher serum 1,25(OH)2D3 levels than the normocalciuric group (p<0.001) and first SFs (p=0.050). In the adjusted multiple linear regression analysis, serum 1,25(OH)2D3 level (beta=0.259, p<0.001) and serum PTH level (beta=-0.160, p<0.001) were significantly correlated with urinary calcium excretion. The patients in highest tertile of 1,25(OH)2D3 had a more than 3.1 fold risk of hypercalciuria than those in the lowest tertile (odds ratio=3.14, 95% confidence interval: 1.431-6.888, p=0.004). No correlation was observed between PTH and 1,25(OH)2D3 (R=0.005, p=0.929) in calcium SFs, while a negative correlation was found in controls (R=-0.269, p=0.001). CONCLUSION: 1,25(OH)2D3 was closely correlated with urinary calcium excretion, and high 1,25(OH)2D3 levels were detected in the hypercalciuric group and in recurrent SFs. However, 1,25(OH)2D3 was not correlated with PTH in calcium SFs. These findings suggest that 1,25(OH)2D3 might be important intrinsic factor for altered calcium regulation in SFs.
Adult ; Calcium/metabolism/*urine ; Female ; Humans ; Kidney Calculi ; Linear Models ; Male ; Middle Aged ; Multivariate Analysis ; Odds Ratio ; Parathyroid Hormone/blood/*physiology/urine ; Vitamin D/*analogs & derivatives/blood/physiology/urine

BACKGROUNDWith recognition of the important roles of Vitamin D (VitD) in various physiological processes, increasing attention has been drawn to the status of VitD in early life. However, the VitD status of young children and the related factors in rural areas of Southwestern China remain unclear. This study aimed to explore VitD status and its seasonal variation in 18-month-old children living in rural Southwestern China. The association of VitD with biochemical and anthropometric variables was also investigated.

METHODSA total of 177 18-month-old children in a rural area of Yunnan Province, Southwestern China, were enrolled. Serum concentrations of 25-hydroxy Vitamin D (25(OH)D) were measured through high-performance liquid chromatogram-tandem mass spectrometry. Parathyroid hormone (PTH) levels were measured with a chemiluminescence assay. Serum concentrations of calcium, phosphorus, and alkaline phosphatase (ALP) were also measured. Anthropometric data and the outdoor activity time of each participant were collected.

RESULTSThe serum 25(OH)D concentration was 26.61 ± 7.26 ng/ml; concentrations lower than 30 ng/ml accounted for 70.6% of the participants and concentrations lower than 20 ng/ml accounted for 16.4%. The level of serum 25(OH)D was not significantly different among four seasons (P >0.05). A positive relationship was found between 25(OH)D concentration and the time of outdoor activities (r = 0.168, P < 0.05). Serum PTH concentration was negatively correlated with 25(OH)D concentration (r = -0.163, P < 0.05). A positive relationship was found between the serum concentrations of 25(OH)D and calcium (r = 0.154, P < 0.05). No significant association was observed between 25(OH)D and ALP, phosphorus, or anthropometric variables.

CONCLUSIONSThe prevalence of VitD insufficiency is high among young children in the rural Southwestern China regardless of the seasons. VitD supplementation is still essential to maintain VitD sufficiency for children living in rural area.

Anthropometry ; China ; Chromatography, High Pressure Liquid ; Cross-Sectional Studies ; Dietary Supplements ; Female ; Humans ; Infant ; Male ; Parathyroid Hormone ; blood ; Vitamin D ; analogs & derivatives ; blood ; Vitamin D Deficiency ; blood ; drug therapy

Firstly, parathyroid hormone (1-14) [PTH (1-14)] analogue containing various alpha-amino-iso-butyric acid residue (Aib) was synthesized by exchanging the 1st and 3rd Ala residues of alpha carbon of PTH (1-14). This analogue revealed to have the quite tight and stable alpha-helical structure using the nuclear magnetic resonance (NMR) analysis. The biological activities of these analogues were examined using a cAMP-generating assay in LLC-PK1 cell lines stably transfected with the wild-type human PTH1 receptor. Only the PTH analogue substituted with methyl moiety without acetylation showed significant cAMP generating action with 15.0 +/- 3.414 of EC50. Then, we used an ovariectomized rat model system to compare the in vivo effects of parathyroid hormone analogue with that of PTH (1-84). Daily subcutaneous administration of the unacetylated Aib1,3PTH (1-14) for 5 weeks in 30 nM/kg subcutaneously with positive control group receiving PTH (1-84) with 8 nM/ kg were performed. However, there was no significant change in spinal or femoral bone mineral density assessed by dual x-ray absorptiometry (DXA) in the Aib1,3PTH (1-14) group where definite increase of these parameters shown in the PTH (1-84) group (p < 0.001). Assessment of bone strength was evaluated with no significant differences among all groups. It was quite disappointing to see the actual discrepancies between the result of significant pharmacokinetic potency and the in vivo clinical effect of the Aib1,3PTH (1-14). However, there are several limitations to mention, such as the short duration of treatment, matter of dosage, and insufficient effect of tight alpha-helical structures with absence of C-terminus. In conclusion, our findings suggest that unacetylated Aib1,3PTH (1-14) did not exhibit any anabolic effects at the bones of ovariectomized rats.
Transfection ; Time Factors ; Structure-Activity Relationship ; Stress, Mechanical ; Spectrometry, X-Ray Emission ; Rats ; Protein Structure, Tertiary ; Protein Structure, Secondary ; Protein Conformation ; Protein Binding ; Peptides/chemistry ; Parathyroid Hormone/*analogs & derivatives/chemistry/*metabolism ; Molecular Sequence Data ; Molecular Conformation ; Models, Statistical ; Models, Molecular ; Magnetic Resonance Spectroscopy ; LLC-PK1 Cells ; Humans ; Female ; Dose-Response Relationship, Drug ; Densitometry ; Cyclic AMP/metabolism ; Cell Line ; Bone and Bones/metabolism ; Bone Density ; Biomechanics ; Animals ; Aminoisobutyric Acids/*metabolism ; Amino Acid Sequence ; Alanine/chemistry