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Objective To understand the current status of osteoporosis risk and influencing factors for residents from 30 to 65 years old in typical hot spring areas in Guizhou province, and to provide a theoretical basis for reducing the risk of osteoporosis and the prevention of osteoporosis in the population. Methods A health questionnaire for residents in typical hot spring areas in Guizhou, osteoporosis risk test questions, Pittsburgh sleep quality index(PSQI), etc were used. A face-to-face survey of 3 708 residents was conducted, and logistic regression was used to analyze the influencing factors of osteoporosis risk in hot spring areas. Results 2 403(64.81%)residents of 3 708 people surveyed were at risk of osteoporosis, of whom 1 434(87.4%)males and 969 females(47.1%)had a higher risk of osteoporosis (χ2=652.4, P < 0.001). As age increased, more residents were at risk of osteoporosis(χ2=273.4, P < 0.001), and numbers of residents of 30-39 years old, 40-59 years old, and above 60 years of age at risk of osteoporosis were 319(49.2%), 1 572(62.9%), and 512(93.6%). Male osteoporosis risk was negatively correlated with an education level of undergraduate and above(OR=0.37, 95%CI: 0.19-0.73). Age 40-59(OR=1.54, 95%CI: 1.07-2.22), 60 and above(OR=6.39, 95%CI: 2.76-14.79), and sleep disorders(OR=1.59, 95%CI: 1.08-2.35)may increase the risk of osteoporosis in male residents in hot spring areas. Less oil in daily diet may increase the risk of osteoporosis in women(OR=1.70, 95%CI: 1.23-2.36). Age 40-59(OR=1.54, 95%CI: 1.17-2.03), over 60 and above(OR=16.24, 95%CI: 10.10-26.12), and sleep disorders(OR=1.84, 95%CI: 1.48-2.28)were positively correlated with risk of osteoporosis in women. Women with junior high school degree(OR=0.61, 95%CI: 0.47-0.80), high school degree(OR=0.57, 95%CI: 0.37-0.89)and undergraduate degree and above(OR=0.59, 95%CI: 0.39-0.98)had a lower risk of osteoporosis than women who were illiterate or semi-illiterate. The osteoporosis risk test questions showed that smoking, heavy drinking, and erectile dysfunction and reduced sexual desire were the main sources of osteoporosis risk in men. Menopause before the age of 60, ≤45 years old, no milk and no calcium supplements, parents with osteoporosis or bone fractures were the major risk sources of osteoporosis in women. Conclusion The risk of osteoporosis among male residents from 30 to 65 years old in typical hot spring areas in Guizhou province is higher than that among women. Education of osteoporosis prevention should be strengthened among local residents to promote healthy behaviors and lifestyles.
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Objective To investigate the prevalence of osteoarthrosis and the association between hot spring bathing and osteoarthrosis among local adults in typical hot spring areas of Guizhou Province. Methods A face-to-face questionnaire survey was conducted among residents aged from 30 to 65 in five typical hot spring areas, including Xifeng(Xifeng County, Guiyang), Jianhe(Jianhe County, Qiandongnan), Fodingshan(Shiqian County, Tongren), Guiyu(Wudang District, Guiyang)and Huishangu(Suiyang County, Zunyi). Residents' basic information, bone and joint diseases prevalence, hot spring bathing, and other health-related behaviors were investigated in this study. The prevalence of local bone and joint diseases was analyzed, and binary logistic regression was used to calculate OR(95%CI)to analyze the association between hot spring bathing and bone and joint diseases. Results A total of 3 708 adults(1 648 males and 2 060 females)were included as the statistical analysis survey subjects, and 794 people reported bone and joint diseases, accounting for a prevalence rate of 21.41%, 95% CI: 0.201-0.227. The prevalence of females(24.56%)was higher than that of males(17.48%)(P < 0.001). The prevalence rates of diseases increased with age(χtrend2=130.265, P < 0.001). There were also statistically significant differences in the prevalence rate of bone and joint diseases among different genders, age groups, occupations, education levels, and smoking behaviors(P < 0.05). After gender, age, occupation, education and smoking were adjusted for, compared with the group who never took hot spring baths, participants who took hot spring baths occasionally(OR=0.793, 95%CI: 0.631-0.996)and frequently(OR=0.713, 95%CI: 0.536-0.948)were associated with a lower risk of bone and joint diseases. Conclusion The prevalence of osteoarthrosis is 21.41% in the typical hot spring areas of Guizhou Province. Older or females have a higher risk of prevalence of bone and joint diseases. Hot spring bathing may be associated with a lower risk of bone and joint diseases.
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Objective To investigate the association between hot spring bathing behavior and hypertension and understand the mediation effect of sleep quality problems on the association. Methods A cross-sectional survey was conducted among adults aged 30 to 65 living and working around five hot springs in Guizhou Province, employing a self-designed questionnaire on the health status and hot spring bathing, and 3 708 qualified questionnaires were collected. Participants were divided into three groups according to their frequency of hot spring bathing: never, occasionally, and frequently. Stratified via sex and sleep quality, the binary logistic regression model was used to analyze the association between different hot spring bathing frequencies and self-reported hypertension. Results Significant difference was detected in the self-reported hypertension between groups who never bathe(13.7%), who occasional bathe(9.4%)and who frequently bathe(8.5%)among female participants(χ2=10.460, P=0.005). However, no significant difference was found among different bathing groups in males. Furthermore, multivariate analysis showed that compared with no bathing, occasional(OR=0.692)and frequent (OR=0.594)hot spring bathing were associated with lower hypertension prevalence among female population, and female groups of occasional and frequent bathing with sleep quality problems had smaller OR(OR=0.571 and 0.406, respectively). After sleep quality problems were included, hot spring bathing was still associated with lower hypertension risk, and the OR values of occasional bathing and frequent bathing groups were 0.723 and 0.611, respectively. The sleep quality problems of female population played a partial mediating role in the association between hot spring bathing and hypertension, and the relative mediating effects of occasional bathing and frequent bathing with hypertension were both statistically significant(Zm=-2.022 and -1.995, P < 0.05), which accounted for 34.34% and 30.15% of the total effects, respectively. Conclusion Regular hot spring bathing may play an auxiliary role in the prevention of hypertension, and it may provide a stronger protection for women, and especially those with sleep quality problems. Sleep quality problems may explain part of the association between hot spring bathing and hypertension in female population.
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Objective To analyze the association between hot spring bathing and the quality of life of smokers living in typical hot spring areas of Guizhou to make suggestions on improving their quality of life. Methods The study is a cross-sectional study whose data was collected by questionnaires. The WHO Quality of Life Scale(WHO QOL-BREEF)was used to measure quality of life. Results The quality of life in the psychological domain(14.09±1.83 vs 13.79±1.82, P < 0.05)and the environmental domain(12.70±1.84 vs 12.37±1.67, P < 0.05)among smokers who took hot spring baths was significantly higher than that among those who did not. After adopting ordinary logistic regression model to adjust for other factors, for the physical domain, the odd of scoring"good"in the WHO scale in group of smokers who took hot spring baths less that once a month was 0.70 lower than that in those who took baths at least once a month(OR=0.70, 95%CI: 0.54-0.91). In psychological domain, the odd of the group of smokers who did not take hot spring baths was 0.65 lower than that in those who took baths at least once a month(OR=0.65, 95%CI: 0.47-0.90). And the odd of the group of smokers who bathed less than once in a month was 0.71 lower than those who bathed at least once a month(OR=0.71, 95%CI: 0.54-0.92). Conclusion There is a positive relationship between hot spring bathing and quality of life, which prompts that people who smoke take hot spring baths to improve their quality of life.
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Objective To investigate hot spring bathing behavior and chronic disease prevalence of residents aged 30 to 65 in typical hot spring areas of Guizhou Province. Methods Totally 3 708 individuals between 30 and 65 in five typical hot spring areas of Guizhou Province were included in this study. Their hot spring bathing behavior and chronic disease prevalence were recorded. Unconditional logistic regression was used to analyze the association between hot spring bathing and the incidence of chronic diseases. Results 71.3% of the residents in the hot spring areas had bathed in hot springs, with the proportion higher in males than females(χ2=92.856, P < 0.001). 76.3% of people took hot spring baths fewer than or equal to 6 times per year, 30.8% of residents often chose to take hot spring baths in the evening, and 37.6% of the residents took hot spring baths for 21-40 minutes. Bathing was more common in winter. 11.5% and 17.9% of the residents added other substances and used hot spring facilities, and most of them added traditional Chinese medicine and used the sauna. 46.6% and 41.6 % of the residents took hot spring baths to relax and relieve fatigue. The self-reported prevalence rate of chronic diseases was 522.1‰, and the top five single diseases were lumbar intervertebral disc disease(119.7‰), hypertension(118.1‰), urinary calculus(77.7‰), cervical intervertebral disc disease(53.7‰)and osteogenesis(44.5‰). Compared with those who never bathed in hot springs, taking hot spring baths 7-11 times a year was negatively correlated with chronic diseases.(OR=0.551, 95%CI: 0.345-0.879). Conclusion Hot spring bathing is popular in typical hot spring areas of Guizhou Province, but its frequency is not high. The overall prevalence of chronic diseases is relatively high, and the order of most prevalent chronic diseases is different from that in other areas. Proper hot spring bathing is negatively correlated with chronic diseases.
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Objective:To investigate the effect of Ziziphi Spinosae Semen （ZSS） and Albiziae Flos （AF） on behavior and endoplasmic reticulum stress endoplasmic reticulum stress protein kinase R-like endoplasmic reticulum kinase （PERK）/activated transcription factor 4 （ATF4）/CCAAT enhancer binding protein （CHOP） pathway in depression model rats， and to explore its antidepressant mechanism. Method:The male SD rats were divided into normal group， model group， ZSS-AF high dose， middle dose and low dose groups （16， 8， 4 g·kg<sup>-1</sup>） and Venlafaxine group （0.008 g·kg<sup>-1</sup>）， <italic>n</italic>=15 in each group. Except the normal group， the depression model was established in the rats of other 5 groups by the method of chronic unpredictable mild stress （CUMS） combined with isolated feeding. The normal group and model group were given with distilled water by gavage when modeling， while other groups received corresponding drug by intragastric administration for 21 days. Behavior changes of rats in each group were observed by the open field test and sugar water consumption test on 1<sup>th </sup>and 21<sup>th</sup>day of the experiment. The protein expressions of PERK， CHOP， B-cell lymphoma-2 associated X protein （Bax） and cysteine-containing aspartate-specific proteases-3（Caspase-3） were detected by Western blot（WB）， the ultrastructural changes of the hippocampus were observed by transmission electron microscope， the apoptosis of hippocampal neurons was observed by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL） method. Result:Compared with the normal group， the scores of open field test and sugar water consumption rate in model group rats decreased （<italic>P</italic><0.01）. Compared with the model group， the scores of open field test and water consumption rate increased （<italic>P</italic><0.01） in ZSS-AF groups and Venlafaxine group. Transmission electron microscope showed that the changes of neuronal damage in hippocampal were revealed in the model group， whereas those neuronal damages were relieved in ZSS-AF groups and Venlafaxine group. TUNEL method showed that the number of apoptotic neurons in hippocampal increased in the model group （<italic>P</italic><0.01）， but decreased in ZSS-AFgroups and Venlafaxine group （<italic>P</italic><0.01）. WB results showed that as compared with the normal group， protein expressions of PERK， CHOP， Bax and Caspase-3 were up-regulated significantly in the model group （<italic>P</italic><0.01）， whereas those were down-regulated in ZSS-AF groups and Venlafaxine group （<italic>P</italic><0.05， <italic>P</italic><0.01）. Conclusion:The antidepressant effect of ZSS-AF herbal pair may be correlated with the regulation of endoplasmic reticulum stress PERK/ATF4/-CHOP pathway.
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Durio zibethnus is mainly distributed in Southeast Asia. Traditional Chinese medicine believes that durian shells have the effects of clearing heat and purging fire, nourishing yin and moisturizing dryness. Therefore, it is often used as a pharmaceutic food in the Chinese folk to assist treating diseases. At present, the chemical constituents isolated from durian shell include phenolic acids, phenolic glycosides, flavonoids, coumarins, triterpenes, simple glycosides and other compounds. Modern pharmacological studies show that durian shell has many pharmacological activities, such as antioxidant, anti-inflammatory, regulation of glucose and lipid metabolism. The chemical composition and pharmacological effects of durian shells are summarized in order to provide references for the further research and application of durian shell.
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<p><b>OBJECTIVE</b>To evaluate the efficacy of targeted tidal volume ventilation in the treatment of severe neonatal respiratory distress syndrome (RDS).</p><p><b>METHODS</b>Eighty-four neonates with severe RDS between June 2008 and January 2010 were randomly assigned to 3 groups according to the ventilation mode: synchronized intermittent positive pressure ventilation plus volume guarantee (SIPPV+VG; n=31), high frequency oscillation ventilation (HFOV; n=23) and intermittent mandatory ventilation (IMV; n=30). The oxygenation status, the durations of oxygen exposure and ventilation and the incidence of complications were observed.</p><p><b>RESULTS</b>The oxygenation status (P/F and a/APO2) in the SIPPV+VG and the HFOV groups was improved significantly 12 hrs after ventilation (P<0.05). While in the IMV group, the oxygenation status was not improved until 24 hrs after ventilation. The durations of oxygen exposure and ventilation in the SIPPV+VG and the HFOV groups were shorter than in the IMV group (P<0.05). The incidences of air leak syndrome and ventilation-associated pneumonia (VAP) were lower in the SIPPV+VG and the HFOV groups than in the IMV group (P<0.05). The incidence of severe intracranial hemorrhage in the HFOV group was higher than in the other two groups (P<0.05).</p><p><b>CONCLUSIONS</b>Compared with IMV, SIPPV+VG and HFOV can improve the oxygenation status more quickly, shorten the ventilation duration and decrease the incidences of air leak syndrome and VAP in neonates with severe RDS.</p>
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Female , Humans , Infant, Newborn , Male , Intermittent Positive-Pressure Breathing , Respiration, Artificial , Respiratory Distress Syndrome, Newborn , Therapeutics , Tidal VolumeABSTRACT
<p><b>AIM</b>To investigate the effect of fractalkine on cell proliferation of cultured rat pulmonary artery smooth muscle cells (PASMCs) in vitro.</p><p><b>METHODS</b>Rat PASMCs were cultured in vitro, and treated with different concentrations (10(-10), 10(-9), 10(-8) mol/L) of fractalkine for 12 h, 24 h and 48 h. The cell proliferation was quantified by MTT assay. The cell cycle of PASMCs was measured by flow cytometric(FCM) analysis.</p><p><b>RESULTS</b>MTT assay showed that fractalkine promoted significantly the proliferation of PASMCs, and the effect was concentration-dependent. FCM analysis indicated that fractalkine increased the percentage of S phase and proliferative index (PI). The percentage of S phase and PI of PASMCs were increased after treated with fractalkine for 12 hours, which reached a maximal level at 24 hours.</p><p><b>CONCLUSION</b>Fractalkine promotes rat PASMCs proliferation in a concentration-dependent manner.</p>
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Animals , Male , Rats , Cell Proliferation , Cells, Cultured , Chemokine CX3CL1 , Pharmacology , Muscle, Smooth, Vascular , Cell Biology , Myocytes, Smooth Muscle , Cell Biology , Pulmonary Artery , Cell Biology , Rats, Sprague-DawleyABSTRACT
<p><b>AIM</b>To study the therapeutic effects of oxyphenamone, a novel inodilator, on myocardial ischemia.</p><p><b>METHODS</b>The cardiac hemodynamic variables in cats with acute myocardial infarction induced by occlusion of the left anterior descending coronary artery (LAD) were recorded with a physiological polygraph and electromagnetic flowmeter. A model of myocardial necrosis induced by subcutaneous injection of isoproterenol was used for evaluating the effects of drugs on myocardial enzymes and morphological change.</p><p><b>RESULTS</b>Intravenous injection of oxyphenamone (2 - 8 mg x kg(-1)) dose-dependently decreased heart rate, mean arterial pressure, vascular resistance and the parameters of myocardial oxygen consumption (tension time index, TTI) in cats with myocardial infarction. It increased myocardial contractile force and cardiac output transiently but showed no influence on the left ventricular pressure and cardiac work. The changes of myocardial morphology, creatine phosphate kinase (CPK), malodialdehyde (MDA) and serum glutamic-oxaloacetic transaminase (GOT) induced by isoproterenol in rats were diminished by intraperitoneal injection of oxyphenamone (4 - 8 mg x kg(-1)).</p><p><b>CONCLUSION</b>By the examination of the cardiac hemodynamics, myocardial enzymes and morphology, it showed that the myocardial damage induced by ischemia or beta-agonist can be antagonized markedly by oxyphenamone, indicating that oxyphenamone may be beneficial for the treatment of myocardial infarction.</p>
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Animals , Cats , Male , Rats , Blood Pressure , Cardiac Output , Cardiotonic Agents , Pharmacology , Heart , Heart Rate , Myocardial Contraction , Myocardial Infarction , Pathology , Myocardium , Metabolism , Pathology , Organic Chemicals , Pharmacology , Rats, Wistar , Vasodilator Agents , PharmacologyABSTRACT
<p><b>AIM</b>To study the protective effect of oxyphenamone, a novel inodilator against myocardial ischemia-reperfusion injury.</p><p><b>METHODS</b>A model of regional myocardial ischemia-reperfusion injury was established by ligating the left anterior desending coronary artery (LAD) in rat heart 10 min followed by reperfusion 15 min in vitro or 30 min in vivo. The protective effects of oxyphenamone were evaluated from the incidence of arrhythmia and the changes of myocardial creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) activities, malondialdehyde (MDA) content, and myocardial ultrastructure.</p><p><b>RESULTS</b>In preparations of rat Langendorff hearts, infusion of oxyphenamone (1-10 micromol.L(-1)) diminished the incidence of ventricular fibrillation, decreased the activities of CPK and LDH in coronary efflux, and antagonized the increase of MDA content in ischemic myocardium significantly. The ischemia-reperfusion injury in anesthetized rats produced severe ventricular arrhythmia, decrease of CPK in myocardium, increase of CPK in serum, increase both of LDH and MDA both in myocardium and in serum, and severe damage of myocardial ultrastructure. Intravenous injection of oxyphenamone 0.1-1.0 mg.kg(-1) 5 min before ischemia ameliorated dose-dependently ventricular arrhythmia, antagonized the changes of CPK, LDH and MDA in both myocardium and serum induced by ischemia-reperfusion. It even maintained these parameters at normal level. The effects were somewhat similar to that of verapamil 1.0 mg.kg(-1) Intravenous injection of oxyphenamone 0.5 or 1.0 mg.kg(-1) 5 min after ligation of LAD also antagonized the ischemia-reperfusion induced changes in CPK, LDH and MDA in myocardium and serum significantly, and ameliorated the damage of myocardial ultrastructure markedly. The therapeutic effects of oxyphenamone were similar to that of propranolol 2. 0 mg.kg(-1).</p><p><b>CONCLUSION</b>From the examination of ECG, myocardial enzymes and ultrastructure, it appears that oxyphenamone can protect myocardium against ischemia-reperfusion injury induced by occlusion of LAD both in vitro and in vivo.</p>
Subject(s)
Animals , Female , Male , Rats , Creatine Kinase , Blood , Metabolism , In Vitro Techniques , L-Lactate Dehydrogenase , Blood , Metabolism , Malondialdehyde , Blood , Metabolism , Myocardial Ischemia , Myocardial Reperfusion Injury , Metabolism , Pathology , Myocardium , Metabolism , Pathology , Organic Chemicals , Pharmacology , Protective Agents , Pharmacology , Random Allocation , Rats, WistarABSTRACT
<p><b>AIM</b>To ascertain the protective effect of oxyphenamone, a novel inodilator, against myocardial ischemia-reperfusion injury.</p><p><b>METHODS</b>A model of global myocardial ischemia-reperfusion injury (I-R) was established by arresting the infusion to heart 40 min followed by reperfusion 30 min in the preparations of rat Langendorff' s hearts. The protective effects of oxyphenamone were evaluated by the cardiac function, the activity of creatine phosphokinase (CPK) in coronary efflux, the myocardial energy metabolism and antioxidation, the membrane fluidity, the activity of ATPase, the calcium content and ultrastructure of mitochondria.</p><p><b>RESULTS</b>Administration of oxyphenamone to the infused heart before cardiac arrest and during reperfusion ameliorated the decreases of myocardial contractile force and coronary flow and the increase of the activity of CPK in coronary efflux induced by cardiac arrest-reperfusion (A-R). At the concentration of 1-10 micromol x L(-1) oxyphenamone dose-dependently antagonized the decrease of myocardial adenosine triphosphate (ATP) and creatine phosphate (PCr) induced by A-R, increased the activities of myocardial superoxide dismutase (SOD) and glutathione peroxidase (GSH-px), decreased mitochondrial malondialdehyde (MDA) content and increased membrane fluidity, glutathione (GSH) content and the activities of GSH-px and ATPase of mitochondria. The parameters mentioned above even maintained at normal level when high concentration of oxyphenamone (10 micromol x L(-1)) was applied. Oxyphenamone also antagonized the mitochondrial calcium overload and the ultrastructure damage of mitochondria induced by A-R obviously. Addition of oxyphenamone (1-100 micromol x L(-1)) to the system of Fe2+-cysteine or Fe2+-H2O2, which could produce oxygen free radicals, decreased MDA content and increased GSH and membrane fluidity of mitochondria significantly.</p><p><b>CONCLUSION</b>With the results of examinations of the cardiac physiological function, myocardial energy metabolism and antioxidation and the calcium content and ultrastructure of mitochondria, it is indicated that oxyphenamone could protect the isolated rat heart against cardiac arrest-reperfusion injury markedly and the mechanism of its action may be related to the antioxidative effect of this agent.</p>
Subject(s)
Animals , Female , Male , Rats , Calcium , Metabolism , Coronary Circulation , In Vitro Techniques , Membrane Fluidity , Mitochondria, Heart , Metabolism , Physiology , Myocardial Contraction , Myocardial Reperfusion Injury , Metabolism , Myocardium , Metabolism , Organic Chemicals , Pharmacology , Protective Agents , Pharmacology , Random Allocation , Rats, WistarABSTRACT
<p><b>BACKGROUND</b>Little is known about the role of dual angiotensin II forming pathways during heart failure. In the present study, the changes of chymase and angiotensin converting enzyme (ACE) expressions in the failing hearts of hamsters were analysed.</p><p><b>METHODS</b>Heart failure was induced by ligation of left anterior descending branch of the coronary artery. Chymase, ACE and angiotensin II type 1 receptor (AT1R) mRNA levels were analysed by reverse transcription polymerase chain reaction (RT-PCR). The activities of chymase and ACE were determined by radioimmunoassay (RIA). Myocardial collagen fibre analysis was performed under optical microscope.</p><p><b>RESULTS</b>Left ventricular systolic pressure (LVSP) and maximum left ventricular developed pressure increase rate (dp/dtmax, mmHg/s) gradually moved lower at 2, 3, 4 and 8 weeks after operation. On the other hand, left ventricular end-diastolic pressure (LVEDP) increased gradually after operation. Compared with the control group (3.55 +/- 0.06, 4.79 +/- 0.70), the heart weight/body weight ratio in operation group had increased significantly at 4 weeks and 8 weeks (4.28 +/- 0.43, 6.17 +/- 0.73) (P < 0.01). Collagen staining showed that the quantity of myocardial collagen fibre increased significantly in the operation group. RT-PCR showed that the chymase mRNA level in the operation group was consistently greater than that in the control group. AT1R mRNA level was also increased significantly at 3 weeks and 4 weeks, both being 1.3 times that of the control group (P < 0.01), whereas ACE mRNA level was not changed. Higher activity of chymase was detected in operation group, being 4, 8, 13 and 19 times that of the control group at 2, 3, 4 and 8 weeks (P < 0.01), respectively. ACE activity was also significantly higher at the same time, being 7, 10, 10 and 3.5 times that of the control (P < 0.01). Angiotensin II (Ang II) level in operation group increased significantly, being 2.5, 2.7, 3.5 and 2 times that of the control group at 2, 3, 4 and 8 weeks, respectively (P < 0.01).</p><p><b>CONCLUSIONS</b>A dual Ang II forming pathway from both ACE and chymase in the hamster hearts plays an important role during the development of heart failure. At the decompensatory stage, the reduction of AngII level may be associated with the decrease of ACE activity.</p>
Subject(s)
Animals , Cricetinae , Male , Angiotensin II , Body Weight , Chymases , Heart Failure , Metabolism , Myocardium , Metabolism , Peptidyl-Dipeptidase A , Genetics , Physiology , RNA, Messenger , Receptor, Angiotensin, Type 1 , Genetics , Reverse Transcriptase Polymerase Chain Reaction , Serine Endopeptidases , Genetics , Physiology , Ventricular Function, LeftABSTRACT
<p><b>AIM</b>To investigate the mechanism of the positive inotropic effect of oxyphenamone.</p><p><b>METHODS</b>With the patch clamp technique and whole cell recording, the sodium and L type calcium currents of myocytes isolated from ventricular myocardium of adult guinea pigs were studied.</p><p><b>RESULTS</b>5 - 50 micromol x L(-1)-oxyphenamone not only significantly inhibited Na+ current, but also promoted the process of inactivation and prolonged the recovery time of the inactivation. The action of oxyphenamone on L type calcium channel was dual. The inward calcium current was increased with 2 - 10 micromol x L(-1) oxyphenamone but decreased when the concentration of the drug was elevated to 20 - 50 micromol x L(-1).</p><p><b>CONCLUSION</b>The mechanism of the positive inotropic effect of oxyphenamone is neither due to the activation of sodium channel nor entirely depending upon the activation of L type calcium channel. The effects of inhibiting sodium current and, at a high concentration, blocking L type calcium current suggest that oxyphenamone may have an antiarrhythemia action.</p>