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1.
Plants (Basel) ; 11(16)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36015396

RESUMO

Grafting is an important agricultural practice to control soil-borne diseases, alleviate continuous cropping problems and improve stress tolerance in vegetable industry, but it is relatively less applied in pepper production. A recent study has revealed the key roles of ß-1, 4-glucanase in graft survival. We speculated that the GH9 family gene encoding glucanase may be involved in the obstacles of pepper grafting. Therefore, we performed a systematic analysis of the GH9 family in pepper, tomato and tobacco. A total of 25, 24 and 42 GH9 genes were identified from these three species. Compared with the orthologues of other solanaceous crops, the deduced pepper GH9B3 protein lacks a conserved motif (Motif 5). Promoter cis-element analysis revealed that a wound-responsive element exists in the promoter of tobacco NbGH9B3, but it is absent in the GH9B3 promoter of most solanaceous crops. The auxin-responsive related element is absent in CaGH9B3 promoter, but it presents in the promoter of tobacco, tomato, potato and petunia GH9B3. Tissue and induction expression profiles indicated that GH9 family genes are functionally differentiated. Nine GH9 genes, including CaGH9B3, were detected expressing in pepper stem. The expression patterns of NbGH9B3 and CaGH9B3 in grafting were different in our test condition, with obvious induction in tobacco but repression in pepper. Furthermore, weighted correlation network analysis (WGCNA) revealed 58 transcription factor genes highly co-expressed with NbGH9B3. Eight WRKY binding sites were detected in the promoter of NbGH9B3, and several NbWRKYs were highly co-expressed with NbGH9B3. In conclusion, the missing of Motif 5 in CaGH9B3, and lacking of wound- and auxin-responsive elements in the gene promoter are the potential causes of grafting-related problems in pepper. WRKY family transcription factors could be important regulator of NbGH9B3 in tobacco grafting. Our analysis points out the putative regulators of NbGH9B3, which would be helpful to the functional validation and the study of signal pathways related to grafting in the future.

2.
Front Plant Sci ; 12: 762889, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34745194

RESUMO

Melon (Cucumis melo) is one of the top 10 fruits in the world, and its production often suffers due to soil-borne diseases. Grafting is an effective way to solve this problem. However, graft incompatibility between scion and rootstock limits the application of melon grafting. In this study, the melon was grafted onto eight Cucurbitaceae species (cucumber, pumpkin, melon, luffa, wax gourd, bottle gourd, bitter gourd, and watermelon), and graft compatibility evaluation and anatomical observation were conducted. Taking melon homo-grafted plants as control, melon grafted onto cucumber and pumpkin rootstocks was compatible, while melon grafted onto luffa, wax gourd, bottle gourd, bitter gourd, and watermelon rootstocks was incompatible based on the scion dry weight on day 42 after grafting. Meanwhile, we found that starch-iodine staining of scion stem base is an index to predict graft compatibility earlier, on day 14 after grafting. Further, microsection observations showed that there was more cell proliferation at graft junction of melon hetero-grafted combinations; vascular reconnection occurred in all graft combinations. However, excess callose deposited at graft junction resulted in the blockage of photosynthate transport, thus, leading to starch accumulation in scion stem base, and finally graft incompatibility. In addition, undegraded necrotic layer fragments were observed at graft junctions of melon grafted onto incompatible bitter gourd and watermelon rootstocks. The above results provide clues for the selection and breeding of compatible Cucurbitaceae rootstocks of melon and demonstrate that starch accumulation in scion base and callose deposition at graft junction is associated with melon graft compatibility.

3.
Ecotoxicol Environ Saf ; 226: 112828, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34600289

RESUMO

Vanadium (V) is the fifth most abundant transition metal, elevated levels of V are hazardous to plants. Boron (B) is an essential micronutrient for plants and can mitigate heavy metal toxicity. However, the mechanism used by B to promote tolerance to vanadium is unknown. In this study, a combination of physiological and gene expression analysis was used to explain mechanism of B (75 µM) induced V (40 mg L-1) stress tolerance in watermelon. V stress severely reduced root and shoot growth and increased the accumulation of ROS. B application improved tolerance to V by enhancing the expression of B transporter genes (ClaNIP5;1-1, ClaNIP5;1-2, ClaBOR4) that facilitated B uptake and transport while restricting V transport in plant tissues. At cellular level, the higher V retention in leaves was achieved by cell wall chelation, whereas, the higher V exclusion in vacuole of root cell was driven by elevated vacuolar H+-ATPase, H+-PPase activities, and transcript level of ClaVHP1;1, ClaPDR12-1 and ClaPDR12-2 genes facilitated by B application. Moreover, B application reduced tissue ROS cascade by enhancing antioxidant enzymatic activity and expression of superoxide dismutase (ClaCSD1-1, ClaCSD1-2, ClaCSD3, ClaMSD1) and catalase (ClaCAT2-1, ClaCAT2-2) genes that enhanced the defense mechanism of the V treated plants, improved root and shoot growth and tolerance index of watermelon. In conclusion, we demonstrate that ameliorative effect of B in tolerance to V of watermelon was based on B homeostasis and improved antioxidant defense system. These findings might help to increase watermelon production in V polluted soils.


Assuntos
Antioxidantes , Citrullus , Boro/toxicidade , Citrullus/genética , Folhas de Planta , Raízes de Plantas , Vanádio/toxicidade
4.
Plant Physiol Biochem ; 154: 204-218, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32563044

RESUMO

Boron (B) is an essential trace element that plays a vital role in metabolic and physiological functions of higher plants. The adequate supply of B is important for plant growth and development. Grafting is a technique used to improve the ion uptake and plant growth. In this study, a commercial watermelon cultivar "Zaojia 8424" [Citrullus lanatus (Thunb.) Matsum. and Nakai.] was grafted onto pumpkin (Cucurbita maxima × Cucurbita moschata) rootstock cv. "Qingyan Zhenmu No.1" with an aim to investigate the response of grafted plants to different levels of B supply (0.25 µM, 25 µM and 75 µM B) in the nutrient solution. Self-grafted watermelon plants were used as control. Pumpkin rootstock improved the plant growth, chlorophyll and carotenoid contents, photosynthetic assimilation, stomatal conductance, transpiration rate, B accumulation and up-regulated the expression of NIP5;1, NIP6;1 and B transporter (BOR2, BOR4) genes in the roots and leaves at 25 µM B compared with self-grafted watermelon plants. Moreover, pumpkin rootstock reduced the oxidative stress and cell damage by reducing H2O2 and MDA contents, and down-regulating the expression of PDCD2-1, PDCD2-2 genes. Moreover, it enhanced the antioxidant activity of watermelon by up-regulating the expression of SOD1, SOD2, CAT2-1, and CAT2-2 genes. Based on these observations, we concluded that pumpkin rootstock has ability to improve the plant growth of watermelon by enhancing the B uptake. This study may help adjust the B concentration in the nutrient medium for watermelon production where pumpkin grafted plants are utilized.


Assuntos
Boro/metabolismo , Citrullus/crescimento & desenvolvimento , Cucurbita , Raízes de Plantas , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio
5.
Food Chem ; 316: 126342, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32044706

RESUMO

The types and amounts of volatiles in the fruits of 39 melon cultivars were determined. We identified 146 volatiles, including 55 esters, 23 aldehydes, 30 alcohols, 15 ketones, 6 acids and 17 others. Ethyl acetate, (Z)-6-nonenal and 3,6-(E,Z)-nonadien-1-ol were the most three abundant volatiles (average content > 50 µg/kg FW). Aroma profiles showed significant differences among cultivars. Zhongtian49 and Zhongtian20 had the most abundant aroma components (76) and Jinguniang exhibited the least (23). One non-climacteric inodorus cultivar (Xizhoumi25) had the highest content of total volatiles (1840 µg/kg FW). Principal component analysis clustered the 39 melon cultivars into five groups. This work describes the comparative diversity of melon fruit volatiles for a large number of cultivars. Furthermore, this study could support the selection of cultivars with a flavor that suits the public and also future breeding work towards the genetic improvement of melon flavor.


Assuntos
Cucurbitaceae/química , Compostos Orgânicos Voláteis/análise , Álcoois/análise , Aldeídos/análise , Ésteres/análise , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cetonas/análise , Odorantes/análise , Microextração em Fase Sólida/métodos
6.
J Exp Bot ; 70(20): 5879-5893, 2019 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-31290978

RESUMO

Potassium (K+) is a critical determinant of salinity tolerance, and H2O2 has been recognized as an important signaling molecule that mediates many physiological responses. However, the details of how H2O2 signaling regulates K+ uptake in the root under salt stress remain elusive. In this study, salt-sensitive cucumber and salt-tolerant pumpkin which belong to the same family, Cucurbitaceae, were used to answer the above question. We show that higher salt tolerance in pumpkin was related to its superior ability for K+ uptake and higher H2O2 accumulation in the root apex. Transcriptome analysis showed that salinity induced 5816 (3005 up- and 2811 down-) and 4679 (3965 up- and 714 down-) differentially expressed genes (DEGs) in cucumber and pumpkin, respectively. DEGs encoding NADPH oxidase (respiratory burst oxidase homolog D; RBOHD), 14-3-3 protein (GRF12), plasma membrane H+-ATPase (AHA1), and potassium transporter (HAK5) showed higher expression in pumpkin than in cucumber under salinity stress. Treatment with the NADPH oxidase inhibitor diphenylene iodonium resulted in lower RBOHD, GRF12, AHA1, and HAK5 expression, reduced plasma membrane H+-ATPase activity, and lower K+ uptake, leading to a loss of the salinity tolerance trait in pumpkin. The opposite results were obtained when the plants were pre-treated with exogenous H2O2. Knocking out of RBOHD in pumpkin by CRISPR/Cas9 [clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9] editing of coding sequences resulted in lower root apex H2O2 and K+ content and GRF12, AHA1, and HAK5 expression, ultimately resulting in a salt-sensitive phenotype. However, ectopic expression of pumpkin RBOHD in Arabidopsis led to the opposite effect. Taken together, this study shows that RBOHD-dependent H2O2 signaling in the root apex is important for pumpkin salt tolerance and suggests a novel mechanism that confers this trait, namely RBOHD-mediated transcriptional and post-translational activation of plasma membrane H+-ATPase operating upstream of HAK5 K+ uptake transporters.


Assuntos
Membrana Celular/metabolismo , Cucurbitaceae/metabolismo , Potássio/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Membrana Celular/efeitos dos fármacos , Cucurbita/efeitos dos fármacos , Cucurbita/metabolismo , Cucurbitaceae/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , NADPH Oxidases/antagonistas & inibidores , NADPH Oxidases/metabolismo , Oniocompostos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia
7.
Oncol Lett ; 7(3): 713-716, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24527077

RESUMO

Felty's syndrome (FS) is characterized by the three conditions of rheumatoid arthritis (RA), neutropenia and splenomegaly, and occurs in few cases of longstanding erosive RA. Discriminating between rare occurrences of autoimmune diseases and malignancies is crucial. The present study describes the case of a 17-year-old female with a two-year history of RA, presenting with an irregular fever, hepatosplenomegaly and enlarged lymph nodes. The antinuclear antibody titer was 1:320, while antibody results for anti-dsDNA, anti-Sm and rheumatoid factor were negative. The clinical presentation was similar to that of lymphoma. However, the fluorodeoxyglucose-positron emission tomography and biopsy examinations of the liver and cervical lymph node did not support the diagnosis of lymphoma. According to the laboratory results and clinical symptoms, the differential diagnosis indicated FS, and immunosuppressive agents were administered. Two weeks later, the patient no longer had a fever, and the transaminase levels were normal, associated with shrinkage of the liver and spleen.

9.
Oncol Lett ; 5(4): 1229-1232, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23599768

RESUMO

A previously healthy 34-year-old female presented with a 5-month history of progressive backache and weakness in the left fingers. Magnetic resonance imaging (MRI) showed soft tissue masses in the spinal canal distributed along the nerve course. The patient's baseline laboratory data were normal. Surgical intervention was performed and histological examination identified isolated spinal granulocytic sarcoma (GS). A bone marrow biopsy also presented normal findings. However, the patient developed numbness and pain in the right lower limb two months later. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) showed FDG uptake in the left trapezius muscle, cervix uteri, iliac bone, lymphadenectasis of the pelvic wall and left axillary fossa. Cerebrospinal fluid (CSF) examination allowed a diagnosis of central nervous system leukemia (CNSL). The patient underwent chemotherapy and intrathecal injection, resulting in the elimination of the residual lesion. Correct diagnosis and adequate treatment are essential to achieve optimal results in patients with isolated spinal GS.

10.
Oncol Rep ; 29(5): 1895-901, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23467984

RESUMO

The mitogen-activated protein kinase (MAPK) pathway has a protective function on the management of hematologic malignancies. The aim of this study was to assess whether the induction of MAPK-mediated effects contributes to the therapeutic value of combination sorafenib and daunorubicin (DNR) treatment. Herein, we found that DNR increased phosphorylation of extracellular signal-regulated kinases (ERK1/2) in K562 cells. ERK1/2 activity was blocked by either the mitogen-induced extracellular kinase (MEK) inhibitor U0126 or a multi-kinase inhibitor sorafenib. Of note, sorafenib sensitized K562 to DNR by inhibiting proliferation and inducing apoptosis in a dose-dependent manner which was through blocking the RAF/MEK/ERK pathway. Moreover, K562 cells transfected with a constitutively active MEK2DD plasmid showed increasing IC50 values following DNR treatment compared with control cells. Combination of DNR with MEK inhibitor U0126 synergistically inhibited K562 cell growth. In conclusion, our results indicated that sorafenib sensitized K562 cells to DNR-induced cytotoxicity by downregulating p-ERK1/2 expression. DNR in combination with sorafenib may represent a new and potential therapeutic strategy in treating acute leukemia with high p-ERK1/2 levels.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Daunorrubicina/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Apoptose/efeitos dos fármacos , Butadienos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Daunorrubicina/administração & dosagem , Sinergismo Farmacológico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Células K562 , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Niacinamida/administração & dosagem , Niacinamida/farmacologia , Nitrilas/farmacologia , Compostos de Fenilureia/administração & dosagem , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Sorafenibe , Células U937 , Regulação para Cima/efeitos dos fármacos
11.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 20(1): 48-52, 2012 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-22391163

RESUMO

The aim of this study was to investigate the proliferation-inhibitory and inducing apoptotic effects of decitabine (DAC) on acute promyelocytic leukemia NB4-R2 cells. Cell inhibitory rate was determined by cell proliferation and cytotoxicity assay (WST-1 assay) after NB4-R2 cells were treated with 0.01 - 0.5 µmol/L DAC for 24, 48 and 72 h. Apoptosis of NB4-R2 cells treated with 0.05 - 5 µmol/L DAC for 48 h was detected by flow cytometry with PI staining and AnnexinV/PI staining. Reverse transcription-PCR (RT-PCR) was used to determine the mRNA expression level of MDR1 gene encoding P-glycoprotein (P-gp). The results indicated that DAC (0.01 - 0.5 µmol/L) inhibited the proliferation of NB4-R2 cells in both time- and concentration-dependent manners. The IC(50) of DAC on the viability of NB4-R2 cells after treatment for 48 and 72 h were 0.089 and 0.064 µmol/L respectively. DAC (0.05 - 5 µmol/L) induced NB4-R2 cell apoptosis in dose-dependent manner with down-regulation of MDR 1 gene expression. It is concluded that a low concentration of DAC (< 0.5 µmol/L) inhibits cell proliferation, while higher concentration of DAC (1 or 5 µmol/L) induces apoptosis on NB4-R2 cells, accompanied with reduction of MDR1 levels.


Assuntos
Apoptose/efeitos dos fármacos , Azacitidina/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Leucemia Promielocítica Aguda/patologia , Azacitidina/farmacologia , Linhagem Celular Tumoral , Decitabina , Resistencia a Medicamentos Antineoplásicos , Humanos , Leucemia Promielocítica Aguda/metabolismo , Tretinoína/farmacologia
12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 19(2): 353-7, 2011 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-21518487

RESUMO

This study was aimed to investigate the effect of multikinase inhibitor sorafenib on the proliferation and apoptosis of U937 cells and its possible mechanism. U937 cells were treated with different concentrations of sorafenib for 48 hours. Cell viability was determined by Cell Counting Kit-8; cell apoptosis and cell ratio in cell cycle were detected by flow cytometry with Annexin V/PI staining and PI staining respectively; expressions of GSK-3ß, ß-catenin and cyclin-D1 were assayed by Western blot. The results showed that the proliferation of U937 cells was inhibited by sorafenib in a dose-dependent manner (p < 0.05). Sorafenib induced cell apoptosis and cell cycle G(1)/G(0) arrest. Compared with results of Western blot before treatment, expression of inactivated GSK-3ß, ß-catenin and Cyclin-D1 down-regulated in a dose-dependent manner after treatment with sorafenib, this same changes were observed after up-regulation of inactivated GSK-3ß by LiCl (p < 0.05). It is concluded that sorafenib inhibits the proliferation of U937 cells and induces cell apoptosis through reducing negative regulation of WNT signal pathway on inactivated GSK-3ß and down-regulating ß-catenin and cyclin-D1 level, which result in U937 cell cycle G(1)/G(0) arrest.


Assuntos
Apoptose/efeitos dos fármacos , Benzenossulfonatos/farmacologia , Piridinas/farmacologia , Via de Sinalização Wnt , Proliferação de Células/efeitos dos fármacos , Ciclina D1/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Niacinamida/análogos & derivados , Compostos de Fenilureia , Sorafenibe , Células U937 , beta Catenina/metabolismo
13.
Chinese Journal of Virology ; (6): 355-361, 2009.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-297948

RESUMO

Pigeon circovrius (PiCV) is a member of circovirus, which is usually regarded as an immunosuppression agent. There were reports that pigeons infected by PiCV showed symptoms of lethargy, weight loss, vomiting, diarrhea, respiratory distress, etc. In this study, we established a PCR method for the detection of PiCV DNA. Samples from 5 different farms in Zhejiang Province were examined and samples from a farm in Hangzhou were positive. Furthermore, the genomic segments of 2 strains of PiCV were amplified, cloned and sequenced using designed primers and the complete genomes of the strains were then assembled and named as PiCV-zj1 and PiCV-zj2, respectively. The sequences were deposited in GenBank under the GenBank Accession number of DQ090945 and DQ090944, respectively. Sequence Analysis had shown that the complete genomes of 2 strains of PiCV from Zhejiang Province had 2 039 nucleotides totally in length and common characters of circovirus such as a stem-loop structure and conserved motifs for Rep protein, which were supposed to be related to the replication of the virus. Pairwise comparisons showed that the nucleotide sequence of the genome of PiCV strains from Zhejiang Province had 86%-89.1% identities to that of 11 published PiCV strains, and that the amino acid identities of the replication-associated protein (Rep) and capsid protein (Cap) displayed 92.1%-94.7% and 76.6%-81.4%, respectively. A phylogenic tree was built using PHYLIP with bootstrap support for 1 000 replicates. The result showed that 10 strains from Europe and America formed one big branch and the others from Zhejiang Province and Australia formed the other two, respectively. This was the first report on the detection and full genome sequencing of PiCV in China.


Assuntos
Animais , Sequência de Bases , Infecções por Circoviridae , Virologia , Circovirus , Classificação , Genética , Clonagem Molecular , Columbidae , Virologia , Genoma Viral , Genética , Modelos Genéticos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Proteínas Virais , Genética
14.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-236740

RESUMO

<p><b>OBJECTIVE</b>To study the preparative method of controlled release microspheres incorporating basic fibroblast growth factor (bFGF) and the bioactivities of bFGF, which were released from bFGF microspheres, on the cultured Schwann cells.</p><p><b>METHODS</b>bFGF was microcapsulated with the multiple emulsion encapsulative method using polylactic-co-glycolic acid (PLGA) as coating material. Its morphology, particle size distribution, drug loading, enveloping rate and in vitro release property were studied. The cultured Schwann cells were grouped according to the different ingredients being added to the culture medium of bFGF group or bFGF-PLGA group. Then the cytometry, cytoactivity detection and mitotic cycle analysis of Schwann cells were performed.</p><p><b>RESULTS</b>The morphology and the particle size distribution of the bFGF-PLGA microspheres were even and good. The drug loading and enveloping rate of microspheres were (27.18 x 10(-3))%+/-(0.51 x 10(-3))% and 66.43%+/-1.24%. The release property of microspheres in vitro was good and the overall release rate was 72.47% in 11 days. The in vitro cellular study showed that: at the first 2 days of plate culture, the cell number and viability of the bFGF group were statistically higher than the bFGF-PLGA group; at the 3rd and 4th days of plate culture, the cell number and viability of bFGF and bFGF-PLGA groups showed no difference; at the 6th and 8th days of the plate culture, the cell number and viability of the bFGF-PLGA group were statistically higher than the bFGF group. By flow cytometry examination, at the 2nd day of plate culture, the G2/M+S percentage of bFGF group was statistically higher than the bFGF-PLGA group, at the 4th and 8th days of plate culture, the G2/M+S percentage of the bFGF-PLGA group was statistically higher than the bFGF group.</p><p><b>CONCLUSIONS</b>It is practical to prepare the bFGF-PLGA microspheres with the multiple emulsion encapsulative method. bFGF-PLGA microspheres can preserve the bioactivities of bFGF effectively and promote the proliferation of Schwann cells in a long period because of the controlled release of bFGF from the microspheres.</p>


Assuntos
Animais , Coelhos , Preparações de Ação Retardada , Fator 2 de Crescimento de Fibroblastos , Farmacologia , Técnicas In Vitro , Microesferas , Células de Schwann
15.
Chinese Journal of Traumatology ; (6): 360-365, 2007.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-236749

RESUMO

<p><b>OBJECTIVE</b>To study the change and relationship among bone mineral density (BMD), collagen composition and biomechanical properties of the callus in the healing process of osteoporotic fracture.</p><p><b>METHODS</b>The osteoporotic rat model and fracture model were established through bilateral ovariectomy (OVX) and osteotomy of the middle shaft of the right hind tibiae, respectively. Ninety female SD rats were randomly divided into OVX group and sham group. With the samples of blood and callus, roentgenographic and histological observation were performed for the assessment of the healing progress of the fracture, and the serum concentration of TRAP-5b, proportion of type I collagen, BMD and biomechanical properties of the callus were measured.</p><p><b>RESULTS</b>The OVX group experienced a significant delay of fracture healing. The mean serum concentration of TRAP-5b of rats in the OVX group was much higher than that in the sham group after the operation (P less than 0.05), but the difference at the same time point after fracture was smaller than that before fracture (P less than 0.05). The BMD of the callus in both groups reached the peak value at the 6 th week after fracture while the proportion of the type I collagen and the biomechanical strength reached the peak at the 8th week.</p><p><b>CONCLUSIONS</b>The deficiency of estrogen after the ovariectomy could induce the up-regulation of the osteoclasts activities, whereas the potency of further activation after fracture was depressed. Although the synthesis of collagen together with its mineralization determines the biomechanical properties of new bone, the accumulation of collagen could be assessed as an index in the prediction of biomechanical strength of bones independent of the bone mineral deposition.</p>


Assuntos
Animais , Masculino , Ratos , Fosfatase Ácida , Sangue , Fenômenos Biomecânicos , Densidade Óssea , Calo Ósseo , Fisiologia , Colágeno , Química , Colágeno Tipo I , Sangue , Consolidação da Fratura , Fisiologia , Isoenzimas , Sangue , Ratos Sprague-Dawley , Fosfatase Ácida Resistente a Tartarato
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