Study on the relationship between local muscle fatigue and related metabolic biomarkers in simulated manual lifting / 中国职业医学

{L-End}Objective To analyze the local muscle response under continuous ergonomic workload by simulating manual lifting, and to screen the sensitive metabolic biomarkers during fatigue process. {L-End}Methods A total of 13 healthy male volunteers were selected as the study subjects using simple random sampling method. Study subjects underwent repetitive simulated manual lifting for four periods (T1 to T4), each lasting 12 minutes. The degree of work-related fatigue in the forearm, upper arm, shoulder, back, and leg muscles, and the whole body was accessed using Borg 6-20 Rating of Perceived Exertion (RPE) Scale. The venous blood samples were collected from elbow between each two periods to detect the levels of eight metabolic biomarkers: ammonia, lactate, creatine kinase, lactate dehydrogenase (LDH), C-terminal telopeptide of type Ⅰ collagen (CTX-Ⅰ), C-terminal telopeptide of type Ⅱ collagen (CTX-Ⅱ), cartilage oligomeric matrix protein (COMP), and calcium ions. {L-End}Results The RPE scores of the study subjects for the muscles of five body parts and the whole body increased with the increasing lifting periods (all P<0.01). Fatigue was observed in all target muscles, with overall body fatigue occurring in the T2 period. The levels of ammonia, lactate, creatine kinase, LDH, COMP, and calcium ions in the serum of study subjects were higher in the T1 to T4 periods than in the T0 period (all P<0.05). The serum CTX-Ⅰ level was higher in the T1 and T3 periods than that in the T0 period (all P<0.05) , and the serum CTX-Ⅱ level was higher in the T1, T2 and T4 periods than that in the T0 period (all P<0.05). The level of these eight serum metabolic biomarkers fluctuated during the T1 to T4 periods. The serum creatine kinase level increased with the period of lifting (all P<0.05). The serum lactate level was higher in the T3 period than those in the T1 and T2 periods (all P<0.05). The serum LDH and calcium ion levels were higher in the T2 to T4 periods than that in the T1 period (all P<0.05). The serum COMP level was higher in the T2 and T3 periods than that in the T1 period (all P<0.05). Except for CTX-Ⅰ, the levels of other seven metabolic markers in serum were higher in individuals after fatigue than before fatigue (all P<0.05). {L-End}Conclusion Serum metabolic biomarkers such as ammonia, lactate, creatine kinase, calcium ions, LDH, CTX-Ⅱ, and COMP exhibit significant changes before and after fatigue. These metabolic biomarkers could be used as sensitive biomarkers for evaluating muscle fatigue during repetitive works.

Addition of MTA in a salicylate-based resin root canal sealer to retrograde root-end filling

Aim To evaluate the flow, pH and calcium release of white MTA (WMTA), salicylate-based resin root canal sealer (Sealapex; SEAL) and SEAL containing 10 (SE10) or 20% (SE20) (w/w) of MTA. Methodology Flow test was realized according to ISO 6876 specification. The sealers samples (n= 10) were placed in polyethylene tubes and immersed in deionized water. After 24 hours and 7, 14, and 28 days, the water pH was determined with a pH meter, and calcium release was assessed by atomic absorption spectrophotometry. Results SEAL and WMTA showed respectively the highest and lowest flow rate when compared with the other materials (P<0.05). SE20 showed the highest pH value only in 24h and 7 days periods (p<0.05). In 14- and 28-days periods, SEAL showed the lowest pH value (p<0.05), but there are no differences between other groups (p>0.05). In all periods, WMTA and SEAL respectively showed the highest and lowest calcium release (p<0.05). Conclusions SE20 proves to be an association with better flow and handling than WMTA, with satisfactory potential for alkalinization and calcium release.

The Roles and Mechanisms of SERCA in Skeletal Muscle / 中国生物化学与分子生物学报

Skeletal muscle is an important organ for development and metabolism and its metabolic disor⁃ ders will induce a series of muscle diseases. As an important regulator of the muscle contraction process, Ca

Low expression S100 calcium ion binding protein A6 promoting the proliferation and migration of esophageal adenocarcinoma SK-GT-4 cells / 解剖学报

Objective To explore the effect of S100 calcium ion binding protein A6 (S100A6) on proliferation and migration of esophageal adenocarcinoma SK-GT-4 cells. Methods Lenti viruses were used to construct stable transfected cell lines (shNC and shS100A6). Real-time PCR was used to detect the mRNA expression of S100A6. The inverted microscope and MTT were used to detect cell proliferation. The Transwell assay was used to detect cell migration. Western blotting was used to detect the expression of S100A6, p-ERK, p-Akt and its downstream molecular involved in proliferation and migration. Using U0126 ( inhibitor of MER1/2) and LY294002 ( inhibitor of PI3K) to detect the effect of these two inhibitors on cell proliferation and migration and the expression of p-ERK, p-Akt and its downstream molecular involved in proliferation and migration in shS100A6 cells. Results Stable cell lines of knockdown S100A6 were constructed. Knockdown S100A6 promoted cell proliferation and migration. Western blotting result displayed that in shS100A6 cells, the levels of p-Akt and p-ERK increased, p21 decreased, cyclinDl increased, and the expression of β-catenin and vimentin, increased. U0126 and LY294002 inhibited the migration of shS100A6 cells. U0126 had no effect on the proliferation of shS100A6 cells, however LY294002 could inhibit the proliferation of shS100A6 cells. U0126 treatment on shS100A6 cells could decrease p-ERK and β-catenin expression. After shS100A6 cells treated with LY294002, p-Akt and β-catenin expression decreased, p21 expression increased and the expression of cyclinDl decreased. Conclusion Low expression of S100A6 promotes cell proliferation and migration, which may be mediated by activation of p-Akt regulating cell cycle progression to promote cell proliferation and by activation of p-Akt/p-ERK to regulate β-catenin to promote cell migration.

Cyclovirobuxine D ameliorates aldosterone-induced primary neonatal rat cardiac myocyte injury via Ca / 中国药理学通报

Aim To investigate the protective effect of cyclovirobuxine D(CVB-D) on aldosterone (ALD)-induced primary neonatal rat cardiac myocytes (PNRC-Ms) injury and the possible mechanism. Methods PNRCMs were extracted by trypsin, and the PNRCMs injury model was established by ALD (10 μmol · L

Clinical effect and mechanism of moxibustion combined with western medication for rheumatoid arthritis of liver-kidney deficiency / 中国针灸

OBJECTIVE@#To observe the clinical effect of moxibustion combined with western medication for rheumatoid arthritis (RA) of liver-kidney deficiency, and explore the mechanism of moxibustion for RA.@*METHODS@#A total of 60 patients with RA of liver-kidney deficiency were randomly divided into an observation group and a control group, 30 cases in each group. In the control group，leflunomide tablets were taken orally, once a day. On the base of the treatment as the control group, moxibustion was applied at Sanyinjiao (SP 6), Shenshu (BL 23), Zusanli (ST 36) and @*RESULTS@#After treatment, the TCM syndrome scores, HAQ scores and DAS-28 scores were decreased in the two groups (@*CONCLUSION@#Moxibustion combined with western medication can effectively relieve clinical symptoms, improve quality of life in RA patients, the curative effect is better than simple western medication. And its mechanism may be related to the regulation of serum level of Ca

Research Progress of Gypsum Ustum and Application of Calcium-containing Hemostatic Materials / 中国实验方剂学杂志

Mineral medicine is an indispensable part of traditional Chinese medicine and has a long history of application. Among them， mineral-based hemostatics have been widely applied for the treatment of various hemorrhagic diseases with extensive clinical experience and established efficacy. Gypsum Fibrosum （GF）， a commonly used mineral medicine in clinical， can clear away heat， and relieve anxiety and thirst. Gypsum Ustum （GU） is the processed product of GF after calcining at high temperature. It is mainly composed of anhydrous calcium sulfate （CaSO4） with the functions of moisturizing， promoting muscle growth， astringent sores and hemostasis. GU is often used externally to treat ulcer， itching， eczema， water and fire scalds， trauma bleeding， etc. Studies on the mechanism of hemostasis have shown that Ca2+ （coagulation factor Ⅳ） is involved in many key processes of the internal and external coagulation cascades and can prevent bleeding by regulating platelet activation and aggregation， and promoting the production of insoluble fibrin and the ultimate formation of a blood clot. GF and GU both contain Ca2+ which provide an important material basis of hemostatic effect for both compounds， but GU has a significant hemostatic effect， while GF has no hemostatic effect. After processing， the taste and efficacy of the GF have been obviously changed which reflects the characteristics of processing， but the processing mechanism of GU has not been fully clarified. Therefore， based on studies of GF before and after calcining， this paper focused on these aspects including calcining process， crystal form comparison， element content， efficacy comparison， and summarized various aspects of Ca2+ involved in hemostasis. In addition， the hemostatic properties of other calcium-containing mineral medicines and new calcium-containing hemostatic materials such as calcium alginate， mesoporous calcium silicate and nanogel hemostatic materials were also discussed. The paper aimed to provide a reference for elucidating processing mechanism and clinical dialectical use of GU， also to promote development of new calcium-containing hemostatic materials.

Effects of different calcium supplementation pathways on calcium ion in calcium-free regional citrate anticoagulation-continuous renal replacement therapy: Study protocol for a prospective randomized cross-over trial / 中国组织工程研究

BACKGROUND: When regional citrate anticoagulation (RCA) is used in continuous renal replacement therapy (CRRT), one of the key aspects to achieve safe and effective extracorporeal circulation is the management of calcium ions. For calcium-free RCA-CRRT, there are generally two ways to do this: The deep vein and the venous line. The anticoagulant effects of different calcium supplementation pathways have not yet been explored. OBJECTIVE: In this trial, we would test our hypothesis that compared with the subclavian vein, when calcium was infused through the venous line of blood filter catheter, the arterial iCa2+ was lower. METHODS: This was a prospective, single-center, randomized crossover trial. From December 2018 to December 2019, 48 patients with RCA-CRRT at the Department of Intensive Care Unit of the First Hospital of Lanzhou University were selected. According to the different calcium sites, the patients were randomly divided into two groups. The calcium supplementation order of group A (n=24) was the venous line of the blood filter catheter-subclavian vein. Group B (n=24) was supplemented with subclavian vein-the venous line. Blood gas analysis results were compared using blood gas analyzers before and after replacement of the calcium supplementation route in all cases. The primary measurement outcome was the differences between arterial iCa2+ and post-filtration iCa2+ with different calcium supplementation pathways, and the simultaneous recording of pH, K+, and total hemoglobin. The secondary measurement outcomes were the incidences of catheter dysfunction and hypocalcemia during the intervention. The trial was approved by the Ethics Committee of the First Hospital of Lanzhou University (approval No. LDYYLL2018-165) in December 2018. The study was registered on the China Clinical Trial Registration Center (ChiCTRI 800020046) in December 2018. Sample and data collection time is from December 2018 to November 2019, data analysis time and test completion time is December 2019. DISCUSSION: This is the first trial on the anticoagulant effects of calcium-free RCA-CRRT through different calcium supplement routes. We will confirm that the arterial iCa2+ level is slightly lower when calcium is infused in the venous line of blood filter catheter than in the subclavian vein, and the incidence rates of catheter dysfunction and hypocalcemia will help us to determine which site is safer.

Diethylmorphine effect on action potential and calcium ion current of neonatal rat cardiomyocytes in vitro / 中国组织工程研究

BACKGROUND: Opioids can regulate the changes of membrane potential and Ca2+ current in cardiomyocytes, but whether diacetylmorphine can induce the changes of cardiac rhythm, cell action potential and Ca2+ current has not been reported. OBJECTIVE: To explore the effect of diacetylmorphine on action potential and calcium current of isolated cardiomyocytes from neonatal Sprague-Dawley rats. METHODS: Five concentrations of diacetylmorphine (0, 10-2, 10-3, 10-4, 10-5 mol/L) and 20 mol/L verapamil were used to treat the cardiomyocytes of neonatal Sprague-Dawley rats cultured in vitro. The cells were divided into control group, diacetylmorphine group, diacetylmorphine+verapamil group. The latter two groups were treated with diacetylmorphine and diacetylmorphine+verapamil (20 μmol/L), respectively, while the control group was treated with the same amount of PBS. The study protocol was approved by the Animal Ethics Committee of the First Affiliated Hospital of Xinjiang Medical University on May 21, 2018 with approval No. IACUC201805-K1. RESULTS AND CONCLUSION: At 24 hours of culture with different concentrations of diacetylmorphine, the number of cardiomyocytes with abnormal morphology increased significantly in a dose-dependent manner. When the concentration of diacetylmorphine increased, the number of survived cells decreased, with a reduction in the size of cytoplasm and number of pseudopods, the cell membrane was shrunk and the nuclear structure was blurred. Compared with the control group, when diacetylmorphine was added to intervene with the cardiomyocytes, there was a significant difference in the spontaneous beating frequency and rhythm of cardiomyocytes. The negative value of resting membrane potential decreased, while the time course of action potential increased significantly, and the amplitude of action potential decreased significantly. Compared with the control group, the number of cells with changes in the membrane potential significantly increased in the diacetylmorphine group. The addition of verapamil reduced the number of cells with changes in the membrane potential. Compared with the control group, the number of cells with variation of membrane potential was increased to some extents. These findings suggest that diacetylmorphine can induce cardiomyocyte morphological abnormality, increase the spontaneous beating frequency and rhythm of cardiomyocytes, and change the membrane potential and action potential of cardiomyocytes. Verapamil acts as a calcium channel blocker that can improve the rhythm abnormality of cardiomyocytes induced by diacetylmorphine.

Study on component-target-pathway multiple interactive network to reveal mechanism of Salvia miltiorrhiza in treatment of microcirculation disturbance / 中草药

Objective: To explore the mechanism of Salvia miltiorrhiza in treatment of microcirculatory disturbance based on network pharmacology. Methods: The targets of S. miltiorrhiza’s active components for treatment of microcirculatory disturbance were screened and predicted by utilizing TCMSP, PubChem Search, Genecards database and Swiss target prediction online tool. Cytoscape 3.3.0 software was adopted to construct an active component-microcirculatory disturbance target network. The protein-protein interaction (PPI) network was established by using STRING database. DAVID database was used to analyze metabolism pathway in target gene ontology (GO) biological process, Kyoto encyclopedia of genes and gnomes (KEGG). Results: Totally 65 active components of S. miltiorrhiza and nine related targets were screened. GO and KEGG pathway enrichment analysis revealed that active components of S. miltiorrhiza participated in oxidation-reduction process, cellular calcium ion homeostasis and other biological processes, and S. miltiorrhiza may regulate VEGF signaling pathway, cholinergic synapse signal transduction, oxytocin signaling pathway, aldosterone-regulated sodium reabsorption pathway and so on. Conclusion: This study reflects the characteristics of multi-components, multi-targets, and multi-pathways of S. miltiorrhiza in the treatment of microcirculation disturbance, which may provide new ideas and methodology for further research on the treatment of microcirculatory disturbance using S. miltiorrhiza.

In vitro study on signal transduction in mice spiral ganglion cell stimulated by multi-wavelength laser based on calcium imaging / 中华耳鼻咽喉头颈外科杂志

Objective@#To research the auditory nerve transduction effects under multi-wavelength pulsed laser stimulations within a safe and acceptable signal range.@*Methods@#The real-time detection of intracellular calcium concentration was adopted by specific fluorescent indicator staining based on calcium imager. The spiral ganglion cells of mice were cultured in vitro. After fluorescent indicating, morphologic observation under optical microscope, Fura-2 calcium ion fluorescence excitation, intact morphology cells selection, fixing the optical fiber, the spiral ganglion cells were irradiated by different wavelength laser, including visible light (450 nm) and near infrared light (808 nm,1 065 nm). The intracellular calcium concentration was monitored by calcium ion imaging.@*Results@#When 450 nm laser stimulated spiral ganglion cells, the intracellular calcium concentration was strongly increased, however, for other wavelength laser stimulation, there was no obvious relative response. And the sensitivity expression of the nerve cells under laser was related with the location of laser fiber. Cells closer to the fiber produced more obvious changes in calcium ion concentration, while for cells farther away from the fiber, the change amplitudes were weaker although the number of changes in calcium ion concentration was consistent.@*Conclusion@#The spiral ganglion cells of mice can induce a signal transduction response under the action of laser, and the response has laser wavelength selectivity.

In vitro study on signal transduction in mice spiral ganglion cell stimulated by multi-wavelength laser based on calcium imaging / 中华耳鼻咽喉头颈外科杂志

To research the auditory nerve transduction effects under multi-wavelength pulsed laser stimulations within a safe and acceptable signal range. The real-time detection of intracellular calcium concentration was adopted by specific fluorescent indicator staining based on calcium imager. The spiral ganglion cells of mice were cultured in vitro. After fluorescent indicating, morphologic observation under optical microscope, Fura-2 calcium ion fluorescence excitation, intact morphology cells selection, fixing the optical fiber, the spiral ganglion cells were irradiated by different wavelength laser, including visible light (450 nm) and near infrared light (808 nm,1 065 nm). The intracellular calcium concentration was monitored by calcium ion imaging. When 450 nm laser stimulated spiral ganglion cells, the intracellular calcium concentration was strongly increased, however, for other wavelength laser stimulation, there was no obvious relative response. And the sensitivity expression of the nerve cells under laser was related with the location of laser fiber. Cells closer to the fiber produced more obvious changes in calcium ion concentration, while for cells farther away from the fiber, the change amplitudes were weaker although the number of changes in calcium ion concentration was consistent. The spiral ganglion cells of mice can induce a signal transduction response under the action of laser, and the response has laser wavelength selectivity.

Role of Ca~(2+)/CaN signaling pathway in BPA-induced IL-6 secretion in macrophages / 中国职业医学

OBJECTIVE: To investigate the mechanism of calcium ion(Ca~(2+))/calcineurin(CaN) signaling pathway in bisphenol A(BPA)-induced interleukin-6(IL-6) secretion in macrophages. METHODS: Raw 264.7 cells in logarithmic growth phase were divided into control group, activator group, BPA low-, medium-and high-dose groups and inhibitor group. The cells in control group were treated with 0.10% dimethyl sulfoxide. The activator group was treated with lipopolysaccharide at mass concentration of 2 mg/L. The 3 BPA groups were treated with BPA at final concentrations of 1, 10, or 100 μmol/L. Two sets of verapamil or tacrolimus(FK506) groups were given verapamil at the final concentration of 10 or 30 μmol/L; or final concentration of FK506 at 250 or 500 nmol/L. Then the cells were treated with final concentration of 100 μmol/L BPA. The cells were collected at 4, 12, and 24 hours. The mRNA expression of IL-6 and CaN at 4 and 12 hours were detected by real-time fluorescence quantitative polymerase chain reaction. The relative expression of IL-6 and CaN protein was detected at 24 hours by enzyme-linked immunosorbent assay, and the intracellular Ca~(2+) level was detected at 4 hours using a single-tube multi-function detector. RESULTS: At 12 hours, the mRNA expression of IL-6 in the 100 μmol/L BPA group was higher than that in control group, activator group and the 1 and 10 μmol/L BPA groups(P<0.05), and higher than that in the 10 and 30 μmol/L verapamil groups, and in the 250 and 500 nmol/L FK506 groups(P<0.05). The mRNA expression of CaN in the 100 μmol/L BPA group was higher than that in control group, activator group and 1 and 10 μmol/L BPA groups(P<0.05), and higher than in 10 and 30 μmol/L verapamil groups(P<0.05). The relative expression of IL-6 protein in the 100 μmol/L BPA group was higher than that in control group, activator group and 1 and 10 μmol/L BPA groups(P<0.05). The relative expression of CaN protein in 100 μmol/L BPA group and 10 and 30 μmol/L verapamil groups were higher than that in control group and activator group(P<0.05). The relative expression of CaN protein in the 10 and 30 μmol/L verapamil groups were lower than that in the 100 μmol/L BPA group(P<0.05). The intracellular Ca~(2+) level in the 100 μmol/L BPA group was higher than that in control group and activator group(P<0.05). The intracellular Ca~(2+) level in the 10 μmol/L verapamil group was lower than that in the 100 μmol/L BPA group(P<0.05). CONCLUSION: BPA might promote the secretion of IL-6 through Ca~(2+)/CaN signaling pathway in macrophages.

Study on Protective Effect of Huayu Qutan Decoction on Vascular Dementia / 中国实验方剂学杂志

Objective: To study the protective effect of Huayu Qutan decoction on vascular dementia (VD) gerbils and to explore whether its mechanism is related to Calcium ion-calmodulin-dependent protein kinase Ⅱ (CaMKⅡ)/cyclic adenosine effect element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling pathway. Method: Forty healthy gerbils were randomly divided into sham operation group, model group, low, medium and high dose groups (5.35, 10.7, 21.4 g·kg-1) of removing blood stasis and expelling phlegm. Eight gerbils in each group were divided into model group and removing blood stasis and expelling phlegm group. Gerbils were given corresponding drugs twice a day after operation. Water maze experiment was conducted 21 days later to investigate the spatial learning and memory ability of gerbils. The expression of p-CaMKⅡ/CaMKⅡ, p-CREB/CREB and BDNF in the hippocampus of gerbils were detected by Western blot and immunohistochemistry. Result: Compared with sham operation group, the incubation period and the number of platform trips of gerbil in the model group were significantly reduced, p-CaMKⅡ/CaMKⅡ, p-CREB/CREB, and BDNF protein expression were significantly reduced (PPPConclusion: Huayu Qutan decoction improves the learning and memory abilities of gerbils with vascular dementia, and its mechanism may be related to the activation of CaMKⅡ/CREB/BDNF signaling pathway.

Progress of STIM1, a dynamic calcium signal transducer, in cardiovascular diseases / 中国病理生理杂志

Stromal interaction molecule 1 (STIM1) is a transmembrane protein of the endoplasmic reticulum (ER) , a Ca2+ transducer in ER that activates the store-operated calcium channel.Through Orai1 protein, STIM1 adjusts the intracellular and extracellular calcium concentration.This way is called a store-operated Ca2+ entry.STIM1 plays a key role in phenotypic transformation of vascular smooth muscle cells, proliferation of endothelial cells, myocardial hypertrophy and myocardial fibrosis to regulate lots of cardiovascular diseases, such as atherosclerosis, congestive heart failure and systemic hypertension.STIM1 is closely related to cardiovascular diseases through calcium signal.The research progress of STIM1 in cardiovascular diseases is mainly discussed in this article.

Effects of calcium ion on the migration and osteogenic differentiation of human osteoblasts / 华西口腔医学杂志

OBJECTIVE@#This study aimed to investigate the effect of calcium ion (Ca²⁺) on the migration and osteogenic differentiation of human osteoblasts and explore the proper concentration and correlation mechanism.@*METHODS@#A series of Ca²⁺ solutions with different concentrations was prepared. Osteoblast migration was assessed by Transwell assay, and proliferation was studied via the CCK-8 colorimetric assay. The mRNA expression of osteogenic genes was examined via reverse transcription-polymerase chain reaction (RT-PCR), and the mineralized nodule was examined by alizarin red-S method. After calcium sensitive receptor (CaSR) antagonism, Ca²⁺-induced migration and osteogenic differentiation were analyzed.@*RESULTS@#In the migration experiment, 2, 4, and 6 mmol·L⁻¹ Ca²⁺ could promoted osteoblast migration at three timepoints (8, 16, and 24 h), whereas 10 mmol·L⁻¹ Ca²⁺ considerably inhibited migration at 8 h. The Ca²⁺ concentration range of 2-10 mmol·L⁻¹ could promote proliferation, osteogenic differentiation, and mineralization of human osteoblasts. Moreover, mineralization was predominantly induced by 8 and 10 mmol·L⁻¹ Ca²⁺. CaSR antagonism could reduce Ca²⁺-induced migration and osteogenic differentiation of human osteoblasts.@*CONCLUSIONS@#Low Ca²⁺ concentration favored osteoblast migration, whereas high Ca²⁺ concentration favored osteogenic differentiation. The Ca²⁺ concentrations of 4 and 6 mmol·L⁻¹ could substantially induce osteoblast migration and osteogenic differentiation, and the Ca²⁺-CaSR pathway participated in signal transduction.

Therapeutic effect of cistanche deserticola ethanol extraction in rats with osteoporosis induced by ovariectomy and its mechanism / 吉林大学学报(医学版)

Objective: To explore the therapeutic effect of cistanche deserticola ethanol extraction (CDE) in the rats with osteoporosis induced by ovariectomy, and to clarify its mechanism. Methods: A total of 72 female SD rats were randomly divided into control, model, estradiol (0. 3 g · kg-1), low, middle and high doses (0. 5, 1.0 and 2. 0 mg · kg-1) of CDE groups, and 12 rats in each group. The rat ovaries were removed by operation in the other groups to establish the osteoporosis models, while the same size of fat of the rats in control group was excised. 5 d later, the rats in estradiol group were hypodermicly injected with estradiol, and the rats in CDE groups were orally administrated with corresponding doses of CDE. The same volume of diluted water was given to the rats in control and model groups. After 20 weeks, the density of right femur of the rat was detected with the method of ratio of weight and size; the mechanics index of left femur of the rat was analyzed by bone granulometer; the levels of serum alkaline phosphatase (ALP) and osteocalcin were measured by ELISA; the levels of serum Ca2 and P were detected by automatic biochemical analyzer; the morphology of uterus tissue was observed by HE staining. Results: Compared with model group, the densities of right thighbone of the rats in estradiol group and low, middle and high doses of CDE groups were significantly increased (P0. 05). Compared with model group and low dose of CDE group, the maximum bending forces, the maximun strains, and the bone rigid coefficients in middle and high doses of CDE groups were remarkably increased (P0. 05). Compared with model group, the morphology of uterus tissue of the rats in low, middle and high doses of CDE groups was improved at different degrees. Conclusion: CDE has therapeutic effect on osteoporosis through increasing the levels of serum ALP, osteocalcin and Ca' of the rats.

Evaluating cerebral endothelial dysfunction induced by amyloid based on the time series model / 中国药科大学学报

@#Time series model was developed to investigate the effect and contributions of related biomarkers on the cerebral endothelial dysfunction induced by beta amyloid(Aβ). HCMEC/D3 was incubated with 2. 5 μmol/L Aβ for 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 h, and biomarkers including cytosolic calcium ion, mitochondrial membrane potential(MMP), endothelial nitric oxide synthase(eNOS)and cell viability were determined. Time series model was established to assess the dynamic relationship between the related biomarkers and cell viability and the contribution of different biomarkers to cell damage. Impulse response analysis indicated that after a positive impact on cytosolic calcium ion, cell viability decreased and this impact continued to decline; after a positive impact on endothelial nitric oxide synthase and mitochondrial membrane potential, cell viability increases, which increased rapidly in the early stage, and the rate decreased in later stage. The result of variance decomposition showed that the cytosolic calcium ion played a major role in cerebral endothelial dysfunction induced by Aβ. Combined with the model study, it is concluded that the intervention on the level of cytosolic calcium ion at the early stage may be the possible way to slow the disease progression.

Analysis of Physiologically Active Substances in Rat Spinal Synaptosome / 中国康复理论与实践

@#Objective To analyze the physiologically active substances, named amino acid neurotransmitters, ATP and Ca2+ in rat spinal synaptosomes. Methods The spinal synaptosome was extracted by discontinuous Percoll density gradient centrifugation from a female Sprague-Dawley rat. The amino acid neurotransmitters were determined with high performance liquid chromatography, ATP content, Na+-K+-ATPase activity, Ca2+-Mg2+-ATPase activity and total ATPase activity with ultraviolet spectrophotometer, and Ca2+ concentration with fluorescence spectrophotometer. Results The amino acid neurotransmitters contained mainly aspartic acid, glycine, glutamic acid and r-aminobutyric acid. The concentration of ATP was about 414.7461 μmol/mg, total ATPase activity > Na+-K+-ATPase activity > Ca2+-Mg2+-ATPasese activity. The concentration of Ca2+ could be calculated from absorbancy directly. Conclusion The rat spinal synaptosome contains a variety of physiologically active substances, which can be accurately analyzed to explore their activities.

Involvement of ryanodine receptor in skeletal muscle fatigue / 体力科学

Ryanodine receptors (RyRs) are tetrameric Ca2+ release channels of sarcoplasmic reticulum (SR). This review attempts to detail the key mechanism of RyR channel gating and to discuss the hypothesis that skeletal muscle fatigue, defined as reduced force production, would result from functional changes in both individual RyR channel opening and coupling among RyR channels. Previous studies have shown that RyR channels in skeletal muscle open simultaneously, called coupled gating, because of physical interaction among channels. In this review, mechanisms underlying muscle fatigue are discussed with consideration of the coupling effect. Fatigue mechanisms are thought to be different between acute exercise and long-term exercise training. The impairments in individual channel opening and coupling between RyR channels can occur after acute exercise, leading to decreased SR Ca2+ release and force depression. On the contrary, during long-term exercise training, individual channel opening would be enhanced but coupling between channels would be impaired. If this were to continue for long periods, SR Ca2+ content would reduce, leading to less Ca2+ release and lower force production.