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This study is to investigate the effect of low doses of insulin (1 u x kg(-1)) and selenium (180 microg x kg(-1)) in combination on general physiological parameters and insulin signal molecules in cardiac muscle of STZ-induced diabetic rats. The levels of blood glucose were estimated using One Touch SureStep Blood Glucose meter. HbA1c levels were estimated using microcolumn assay. TG and TC were estimated using enzymatic assay. The levels of PI3K and GLUT4 in cardiac muscle were examined by immunoblotting and immunohistochemistry. The result showed that insulin in combination with selenium could significantly lower blood glucose and blood lipid levels and markedly restored the PI3K and GLUT4 levels in cardiac muscle. It could be concluded that there was cooperation between insulin and selenium, and that treatment of diabetic rats with combined doses of insulin and selenium increased cardiac glucose uptake by upregulating the level of PI3K-mediated GLUT4 in cardiac muscle, eventually ameliorating myocardial dysfunction.
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BACKGROUND: PI3K is a family of enzymes involved in insulin signal transductlon pathway, the abnormal expression of which would affect synthesis, secretion, and migration of GLUT4, therefore, results In increased blood sugar, eventually, leads to diabetes.OBJECTIVE: To discuss the effects of insulin combined with selenium on PI3K and GLUT4 expression in cellular signal transduction of skeletal musde in diabetic rats.METHODS: Sprague Dawley (SD) rats were randomly divided into the control, diabetic, insulin-treated diabetic, selenium-treated diabetic and combination administration groups. All rats were prepared for diabetic models by injecting 50 mg/kg Streptozocin exception of the control group. Rats in the control and diabetic groups ware free to food and water; in the insulin treatment group,rats were subcutaneous injected 1 U/(kg·d) insulin. Rats in the selenium treatment group ware treated with a dose of 180 pg/kg per day of sodium selenite dissolved in redistilled water by gavage; and in the combination administration were given both treatments for 4 successive weeks. The levels PI3K end GLUT4 in skeletal muscle were estimated using Western blotting and immunohistochemistry techniques.RESULTS AND CONCLUSION: Immunohietochemistral results were accordance to Western blotting results, which showed the combination of insulin and selenium can remarkable Increase the levels of PI3K in skeletal muscle and GLUT4 in skeletal muscle membrane fraction, therefore, enhance the insulin signal transduction pathway.
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Objective To evaluate the effect of low-dose insulin [1 U/(kg · d)] in combination with selenium [180 g/(kg · d)] on general physiological parameters and glucose transporter (GLUT4) level in skeletal mnscle of streptozotocin (STZ)-induced diabetic rats. Methods Diabetic rats were treated with insulin, selenium, and insulin and selenium in combination for four weeks. The level of blood glucose was determined using One Tonch SnreStep Blood Glucose meter and the level of GLUT4 in skeletal muscle was examined by immunobiotting and immnnohistochemistry. Results Our data showed that insulin in combination with selenium could significantly lower blood glucose level and restore the disturbance in GLUT4 level in skeletal muscle. Treatment with insulin was only partially effective in restoring diabetic alterations. Conclusion It can be concluded that there is a synergistic action between insulin and selenium, and that treatment of diabetic rats with combined doses of insulin and selenium is effective in the normalization of blood glucose level and correction of altered GLUT4 distribution in skeletal mnscle of diabetic rats.
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The teaching reform on functional experiment is an attractive problem of the medical teaching development at present. Our school has opened the course of functional experiment according to integrating and recombining with physiology, pathologic physiology and pharmacology, which brought into playing a positive role in enhancing the medical students' capability of practice, the comprehensive application of knowledge and the consciousness of innovation. However, some problems still exist and further practice is needed for more improvement.
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Objective To investigate the expression profile of human genes in response to acute sodium arsenite treatment by cDNA microarray. Methods The RNA was purified from the L-02 cells without and with arsenite sodium induction for 2 hours, 15 hours and 24 hours, respectively. Results The hybridization patterns were different between every interval of arsenite induction. Expression of hCYR61 increased after 2 hours' induction, but decreased after 15 hours and 24 hours. Expression of metallothionein Ⅳ and Ⅲ elevated at the whole induction phase. HSP86 was up-regulated after 15 hours and 24 hours' induction, but it did not alter at two hours' induction. Conclusion When exposed to arsenite, the cells are under a meet-an-emergency situation to synthesize the most necessary protein and inhibit synthesis of unessential proteins.
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Objective To investigate the chemical properties of superficial cardiac neurons. Methods By means of immunohistochemical ABC technique,the study was performed concerning the distribution of calcitonin gene-related peptide(CGRP) and substance P(SP) in the canine main cardiac superficial plexus. Results CGRP-immunoreactive(IR) neurons were found in every plexus,but SP-IR neurons could be observed only in dorsal atria plexus(DAP),inter atria plexus(IAP) and aorta-pulmonary plexus(A-PP).The shape and size of CGRP-IR and SP-IR neurons were similar.The comparative study on atria and ventricles indicated that CGRP-IR and SP-IR neurons in atria were more than those in ventricles.Numerous CGRP-IR,SP-IR nerve fibers could be observed in each fat pats and intermyocardiocytes.These nerve fibers were usually situated near blood vessels,or were attached to vessel wall.Somewhat CGRP-IR and SP-IR nerve fibers were connected with myocardiocytes in some regions.Conclusion The results indicated that actually existed two peptides in canine cardiac superficial plexus.These implied that the regulations of the two kinds of peptidergic neurons to atria and ventricle were different.The two kinds of neurons mentioned above were likely to perform different or similar functions in canine heart.CGRP and SP could possibly modulate the activities of myocardiocytes and vessels of heart directly.
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Objective To investigate the protective effect of ascorbic acid on myocardium from ischemia and reperfusion injury and its electrophysiological mechanism. Methods Using modified Ferrier's arrhythmia induced by ischemia and reperfusion injury in isolated guinea pig right ventricular wall. Results Ascorbic acid at 5, 10, 50 and 100μmol/L slightly decrease incidence of ischemia arrhythmia (P ＞ 0. 05). In contrast, ascorbic acid at 10, 50 and 100μmol/L significantly reduced the incidence of arrhythmia during early reperfusion(2～12min) (P ＜ 0. 01 or P ＜ 0. 001). Ascorbic acid at 5～ 100μmol/L didn't reverse the abbrevating of APD of endocardium and epicardium and didn't affect the conduction time in endocardium (P ＞ 0. 05). However, ascorbic acid abbreviated epicardial conduc tion time significantly (P ＜ 0. 05 or P ＜ 0. 01 or P ＜ 0. 001 ). Conclusion The study suggests that ascorbic acid might exert antiarrhythmic effect via alleviating conduction abnormity to avoid transmural reentries during ischemia and early reperfusion.
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AIM: To investigate the electrophysiological characteristics of ventricular myocyte both in subendocardium and in subepicardium during ischemia. METHODS: Using modified Ferrier's method of ischemic and reperfusion injury in isolated guinea pig right ventricular wall. RESULTS: The transmembranal electric activities in subendocardium and in subepicardium were all significantly abnormal, and it was more significant in subendocardium. CONCLUSION: The alteration degree of ventricular myocyte in subendocardium and in subepicardium during ischemia and early reperfusion was different, and this might be the electrophysiological basis of the vulnerability of the subendocardium.
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The Chinese traditional medicine database intelligent inquiry and subject selecting system manages 4 databases of information on disease, herbs, their pharmacological effects and compound prescription intelligently and relatively. When a key word is input into the system, the associated information of herbs, their compound prescription, action and effects can be displayed immediately. The compound prescription can be quantitatively estimated as monarch, minister, assistant and guide in order. Following all associated data that are collected, the effective density of herbs can be arranged from a line. The design of the system has the characteristics of pertinence, flexibility, exoteric, convenience, friendship, multi-function, which can help investigator to select subject of traditional medicine scientifically. Moreover, it can be updated and extended when required. The system can promote information and modernization of researches on Chinese traditional medicine.
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OBJECTIVE:To observe the decreasing effects of Polydatin on blood viscosity and microcirculation in the rat model of acute blood stasis.METHODS:The rat model of acute blood stasis was established with high dose of adrenaline sub?cutaneous injection in combination with ice-water socking.The parameters such as whole blood viscosity?bat low and high shear rates,hemotocrit,platelet adhesiveness testPAdT,fibrinogenFIB,plasma viscosity?petc.were used.RESULTS:The results showed that Polydatin reduced FIB,PAdT in rat model remarkably.It obviously caused a reduction of?p,which induced decrease of?b.The effect was more significant than any other factors in reducing blood viscosity and improving mi?crocirculation.CONCLUSION:Polydatin is helpful to reduce blood viscosity and improve microcirculation.The data provided would be useful for rational use of drug.
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The effects of ZS on plasma lipids and lipoprotein-cholesterins of rats fed on normal diet and rats fed on rich-fat diet were studied. It was found that ZS at 64 mg/kg?d-1 ip for 20 d could reduce the levels of TC and LDL-c, increase HDL-c and HDL 2 -c of rats fed on normal diet. ZS at same dosage could reduce TG, and increase HDL2-c of rats fed on rich-fat diet. It was demonstrated by this study that ZS could be of great advantage to protection from as in rats.
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Aim To observe effects of Seabuckthorn fatty acids on old rat ovarian granulosa cell apoptosis and expression of bcl-2 and fas,then discuss the adjustive effect of Seabuckthorn fatty acids on ovarian function of menopause.Methods 22 months old rats were randomly divided into 5 groups,estrogen control group,old control group,Seabuckthorn fatty acids group of high dose,middle dose and low dose.In addition,one young control group was made up of 3 months old rats.Rat ovarian granulosa cell apoptosis was detected by TUNEL.The expression of protein bcl-2 and protein fas were detected by immunohistochemistry,and bcl-2 mRNA and fas mRNA by in situ hybridization(ISH).Grey analyse was done using Q550CW image analyse system.Results Compared with the old rats control group,Seabuckthorn fatty acids of high dose,middle dose and low dose can differently restrain rat ovarian granulosa cell apoptosis,enhance the expression of protein bcl-2 and bcl-2 mRNA,weakened the expression of protein fas and fas mRNA.Conclusion Seabuckthorn fatty acids restrains ovarian granulosa cell apoptosis through adjusting the expression of bcl-2 and fas.Sequentially,it adjusts estrogen level and treats menopause syndrome.
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It was found that there were 31?s 13 ganglia or 1983 ?s 331 neurons ( n = 6) in canine right atrial ganglionated plexus (RAGP). Nicotine (100 ?g) was administered to the plexus in 30 anesthetized open-chest dogs. Either positive or negative inotropic and chronotropic responses were elicited. Control injections of 0. 1 m1 NS into RAGP and injections of nicotine (100 ?g and 200?g) did not elicite any cardiac responses. Following acute decentralzation of hearts, nicotine (100 ?g ) was againadministered to RAGP. Some positive and negative responses were still elicited, but frequency of the responses was reduced. It is concluded that nicotine can directly activate efferent sympathetic and parasympathetic neurons of RAGP. and indirectly activate them by stimulation of afferent neurons, these nicotine sensitive cardiac neurons can modulate cardiac function in ifferent tendencies.
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The effects of Dimethyl trilobine Iodide (DTI) on the blood lipids and lipoprotein choieslerol of rats and hemorrheology of rabbits were studied An peritoneal injection of DTI at the dosage of 0.5mg/kg could increase the serum TG of normal rais and reduce the HDL-c and HDL-c/LDL-c of rats fed with normal and fat-rich diets. An intravenous injection of DTI at the dosage of 10?g/kg accelerated formation of thrombus in vitro and at 5?g/kg and 10?g/kg elevated plasma mucosity at high sheafing. It was demonstrated that DTI had probably unfavorable effects on mediation of blood lipids of rats and hemorrheology of rabbits.
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Objective To study the effects of sibutramine on the human-ether-a-go-go-related gene (hERG) current in HEK293 cell line that overexpresses hERG potassium channels. Methods HEK293 cell line that overexpresses hERG potassium channels was constructed. Whole cell patch clamp techniques were employed to investigate the effects of sibutratime on Iherg in the cell line. Results Sibutramine reduced hERG current in a concentration-dependent manner:the inhibition rate was (8.82?2.32)%,(26.7?5.78)%,(44.93?4.60)% and (85.22?3.37)% at the dose of 3,10,30 and 100 ?mol/L. IC50 value was 32.66 ?mol/L (n=8). Ⅰ-Ⅴ relationship was inhibited by sibutramine (3,10,30 and 100 ?mol/L) at membrane potentials from -10 mV to +60 mV (step) and from 0 mV to +60 mV (tail) (n=8). Conclusion Sibutramine significantly inhibited Iherg in HEK293 cell line that overexpresses hERG potassium channels in a concentration-dependent manner,which may be a major mechanism of causing QT interval prolongation.
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Objective To study the protective action of Semen Ziziphi Spiosaeand on acute myocardial ischemia and its effecte on infarcted area. Methods Left anterior descending(LAD) of coronary artery was ligated to cause the big rat's acute myocardial ischemia, and electrocardiogram (ECG) was used to appraise the effect of sour jujube kernel total soap on the myocardial infarcted area. Results Compared with control group, the experimental group treated with sour jujube kernel total soap glucosidal showed significantly smaller infarcted area; and ECG showed the heart rhythm, S-T piece and T wave value were significantly decreased in the experimental group. Conclusion Sour jujube kernel total soap glucosidal can reduce the myocardial infarcted area caused by ligature of LAD, so as to protect the cardiac muscle.
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Objective To investigate the effect of Prunellu vulgaris L.extracts on isolated rabbit artery. Methods The effect of Prunellu vulgaris L.extracts on the contraction curve caused by norepinephrine (NE) was recorded on isolated rabbit artery. Results The contraction curve moved to the right and the maximum contraction range was decreased by chloroform extract, butanol extract and ethyl acetate extract; the contraction curve had no move by aquatic extract. Conclusion Prunellu vulgaris L. has the effect of dilating artery and reducing blood pressure.
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Objective To study the sedative and hypnotic effects of oil of spine date seeds by different extraction technologies(compression and supercritical CO2 extraction,OSDSE and OSDSS) in mice.Equivalence test was used to test the effects.Methods Spontaneous activity and tolerance were observed by photoelectric counting method after long-term intragastric administration of OSDSE and OSDSS in mice.The sleeping time and delitescence induced by above threshold dose of pentobarbital sodium and sleeping number induced by below threshold dose of pentobarbital sodium were utilized to observe the hypnotic effect of OSDSE and OSDSS in mice.Diazepam was applied as a positive control drug.Results OSDSE and OSDSS could obviously reduce spontaneous activity,increase sleeping time and sleeping number in mice,while the sleeping delitescence was shortened.All the effects induced by OSDSE and OSDSS were equivalent.The inhibitory effect of spontaneous activity was enhanced following repeated administration,while the effect of diazepam was reduced.Conclusion Both oils of spine date seeds can induce sedative and hypnotic effects without tolerance.They have equivalent effects on sedation and hypnosis.
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The effects of flavones of epinedium brevicornum maxim (FEBM) on hemorrheological Parameters of rabbits were studied. It was found that FEBM at 0.1 or 0.4g?kg~(-1)?d~(-1)ig b. i. d. could inhibit thrombosis in vitro,at 0.4 g?kg~(-1)? d~(-1) could reduce blood mucosity at 2～40 s~(-1) shearing and inhibit agglutination of red cells. It was demonstrated that the inhibition of thrombosis and the reduction of blood mucosity might be due to the effects of FEBM on agglutination of red cells.
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Objective To compare the specificities of the cell membrane stationary phases(CMSP) with cell membrane chromatography(CMC).Methods Cell chromatographic columns were constructed for both rat aorta tissue cells and cultured rat aorta smooth muscle cells.Then the chromatographic affinities of ten ligands of ?-adrenergic receptor(?-AR) with both said chromatographic columns were investigated.Capacity factors(k'),as a chromatographic parameter,were calculated.Results The correlation analysis showed a positive correlation between the rat aorta tissue CMSP and the cultured rat aorta smooth muscle cell CMSP,with correlation factor of r=0.923,P