Objective Recent.studies have found a strong association of insulin resistance, which might occur during ischemia reperfusion in vitro in the experimental dogs, with disturbed function of cardiomyocytes. Obvious acute insulin resistance, along with glucose dysmetabolism in the reperfused cardiomyocytes, was furher observed in the study performed with ischemia-reperfused ventric- ular myocytes of rats. We tried to investigate preliminarily the molecular mechanisms of insulin resistance in the cardiomyocytes after ischemia reperfusion. Methods An experimental model of insulin-stimulated ischemia reperfusion (SI/R) was created by isolating cardiomyocytes from adult rats. Glucose uptake of the cardiomyoctyes was evaluated with isotope-labeling technique. Glucose trans- porter 4 (GLUT4) translocation induced by insulin was investigated with Western blot analysis, and the intracellular level of free Ca2+ ([Ca2+]I) was measured quantitatively with Ca2+ indicator Fura-2. Results Insulin can stimulated glucose uptake by cardiomyo- cytes, indicating that these cells were insulin-sensitive. Cardiomyocytes were demonstrated notable acute insulin resistmce during reperfusion. Insulin-stimulated GLUT4 translocation in the cardiomyocytes 15 minutes after reperfusion was 72.2% of that in the con- trol group(P<0.05), in which the GLUT4 content in plasma membrane remained unchanged. The finding suggested that a disturbed GLUT4 translocation might happen in the cardiomyocytes during insulin-stimulated ischemia-reperfusion. Calcium overload was identi- fied in the cardiomyocytes with ischemia reperfusion. At 15 minutes of reperfusion, [Ca2+]I was significantly higher in the reperfused cardiomyocytes than that in the control cardiomyocytes[(318.66±23.06)vs(130.70±0.82) nmol/L, P<0.05], and kept at a higher level [(177.79±17.46) nmol/L] at 60 minutes of reperfusion (P<0.05, vs control). Partial correlation analysis revealed a negative correlation of[Ca2+]I with insulin-induced ghcose uptake in the cardiomyoctyes (r = -0.557,P=0.006). Conclusion Disturbed GLUT4 translocation and decreased intrinsic activity may be important molecular mechanisms for the development of insulin resistance in the cardiomyocytes of rat during insulin-simulated ischemia reperfusion,. [Ca2+]I overload may account for the de- creased intrinsic activity d GLUT4.

Objective To evaluate the method of low-intensity anticoagulation therapy in the pregnant women who had received mechanical heart valve replacemant, and the effects of warfarin on the pregnant women and their fetus. Methods This retrospective study involved 56 pregnant women( 61 pregnancies)who had received mechanical heart valve replacement.Their pregnant status, delivery, and anticoagulation therapy were observed and followed-up between May 1986 and November 2009 at West China Hospital of Sichuan University. Results All patients took oral anticoagulant (warfarin) throughout pregnancy. The dose of domestic warfarin was ( 3.02 ± 0.85 ) mg/d ( in 42 cases), and the dose of imported warfarin was (2.84 ± 0.57 )mg/d (in 14 cases). The mean INR value of 401 samples from patients was 1.67 ±0.58. No thromboembolism or major hemorrhagic complications occurred. Minor bleeding occurred in 11 pregnancies. Forty-seven patients had term delivery, 7 had premature birth, 6 had spontaneous abortion, and 1 had intrauterine fetal death. Six newborns were born with low birth weight (2.3 ± 0. 5 ) kg, and no abnormal fetus was observed. Conclusion The low-intensity anticoagulation therapy with warfarin (at a dose of less than 5 mg/d) and a INR target of 1.5 to 2.0 was safe and convenient for the pregnant women,who had received mechanical heart valve replacement. The abnormalities rate of fetus was low.

0.05,vs control).Insulin stimulated glucose transport into cardiomyocytes in a dose-dependent fashion.Glucose uptake stimulated by insulin into cardiomyocytes was both decreased significantly in 15 mins reperfusian group and in 60 mins reperfusion group (P

Mechanical environment seems to be one of the most important surviving environment for vessel conduit and vascular endothelial cells(ECs), while adhesion is one of the most important physical characteristics of ECs. In this study, Flow chambers of steady laminar and turbulent flow are made and improved. Different flow-derived VCAM-1, ICAM-1 expressions are detected by laser confocal microscope. Spacial and temporal curves of the adhesion molecules are protracted. In laminar flow, expression of VCAM-1 is dramatically elevated, whereas the expression of ICAM-1 is transiently elevated and it immediately falls back to the baseline. In turbulent flow, expression of VCAM-1 declines, while expression of ICAM-1 slowly rises to a peak. These results indicate that such pathological flow field as turbulence exerts different influence on the adhesion of vascular ECs from laminar flow, and turbulence could be one of the most important reasons of the ECs structural and functional lesion.
Cell Adhesion ; Cells, Cultured ; Endothelium, Vascular ; cytology ; metabolism ; Epithelial Cells ; cytology ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; biosynthesis ; Microscopy, Confocal ; Stress, Mechanical ; Umbilical Veins ; cytology ; Vascular Cell Adhesion Molecule-1 ; biosynthesis

Lining the inner surface of the walls of blood vessels, Endothelial cells (ECs) go beyond providing selective membrane to maintain the natural structure and function of vessels; they also synthesize varieties of vasoactive proteins to modify the pressure shift in the local flow field and hence they adapt the physiological activities of vessels. In this experiment, ELISA and RT-PCR technologies were adopted. We set up five different pressure loaded ECs groups,one non-activated cultured ECs group and one single shear stress loaded ECs group. Such a design was intended to demonstrate the effects of pressure shift on the expression of vasoactive protein synthesized by ECs [Endothelin-1(ET-1), endothelial Nitric Oxide Synthase (eNOS), Cyclooxygenase-2(COX-2) and Vascular Endothelial Growth Factor(VEGF)]. Our aim was to elucidate the mechanism of the pressure shift mediated dysfunction in ECs and the related dose-effect relationship. Based on these data, we suggest that ECs could modify the expression of vasoactive protein for adapting to the pressure shift in the local flow field; while in the process of--40 cmH2O induced ECs' dysfunction, the vasoactive proteins eNOS, COX-2 and VEGF play an important role in protecting ECs.
Cells, Cultured ; Cyclooxygenase 2 ; genetics ; metabolism ; Endothelial Cells ; metabolism ; physiology ; Endothelin-1 ; genetics ; metabolism ; Humans ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Pressure ; RNA, Messenger ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

In order to establish a method for measuring quantitatively turbulent shear stress (TSS) downstream of mitral stenosis in vivo based on Doppler echocardiography and computer-aided image analysis, we used doppler echocardiography to record the spectrum of flow velocity downstream of mitral valve at several locations in normal persons and in patients with mitral stenosis. With the computer-aided analysis of spectrum images, the magnitude of TSS was measured at the locations. The results demonstrate that no matter how severe the mitral stenosis is, the TSS and relative turbulent intensity(Irel) at the central locations of jet are lower than those at the marginal ones. A significant difference in the quantitative items of TSS, Irel and flow field uniformity between normal persons and patients with varying-degree of mitral stenosis was noticed (P < 0.05). There was a significant correlation between these items and effective orifice area (EOA), and we found that the smaller EOA is, the more severe the extent of stenosis is and the greater the magnitude of both TSS and Irel are, and that the highest magnitude of TSS is focused on the marginal area of jet. These results indicate that there is an obvious correlation between TSS(measured by Doppler echocardiography combined with computer-aided image analysis) and flow field uniformity. They can coincidently reveal the hemodynamic changes resulting from mitral stenosis of varied severeness, implying that our method could exactly depict the magnitude of TSS downstream of mitral stenosis in vivo and is non-invasive and good for anti-disturbance. The method can be used to analyze quantitatively TSS in the flow field of heart valve in patients with valvular diseases.
Adult ; Blood Flow Velocity ; Echocardiography, Doppler ; methods ; Female ; Humans ; Image Processing, Computer-Assisted ; Male ; Middle Aged ; Mitral Valve Stenosis ; diagnostic imaging ; physiopathology ; Stress, Mechanical

This study was aimed to compare the differences of adhesion properties of endothelial cells (EC) from arteries (AEC), veins (VEC) and capillaries (MVEC) under shear stress condition, and to explore whether they can get the same adhesive ability as graft in similar shear stress conditions. With mended parallel plate flow apparatus and peristalsis pump providing fluid shear stress used, endothelial culture models were established in vitro with the same environmental factors as steady culture. To compare the adhesion among three kinds of endothelial cells under dynamic condition and static condition, the dynamic change of cytoskeletal actin filaments and the effects of different adhesive proteins coated on the adhesion of EC to the glass were studied. The cultured endothelial cells under flow conditions were extended and arranged along the direction of flow. The adhesive ability from high to low under static condition were AEC, MVEC and VEC (VEC compared with AEC or MVEC, P < 0.05), sequentially. The adhesion of endothelial cells from variety sources under dynamic culture condition was significantly increased than that of the static groups. The ratio of cell retention was not significantly different between AEC and MVEC. But VEC was significantly different (P < 0.05) compared with AEC or MVEC. The actin filaments (F-actin) were bundled together and arranged along the direction of flow after fluid culture. Dense peripheral band (DPB) gradually disappeared and distinct stress fibers were formed, which even interconnected to form a whole in the MVEC. The adhesion of AEC, VEC and MVEC under shear stress conditions are more significantly increased than those under the static culture conditions, and the MVEC can achieve the same adhesion as AEC.
Arteries ; cytology ; Capillaries ; cytology ; Cell Adhesion ; Cell Culture Techniques ; methods ; Cells, Cultured ; Cytoskeleton ; physiology ; Endothelial Cells ; cytology ; physiology ; Humans ; Shear Strength ; Stress, Mechanical ; Veins ; cytology

This study was conducted to modify the method for establishing the model of myocardial infarction by ligation of the left anterior descending branch (LAD) of coronary artery in rats, and then observations on them were made with the use of electrocardiography, heart function exam and histomorphology. 30 adult male inbred strain Wistar rats were randomly divided into two groups: sham group (n = 5) and model group (n = 25). Each rat in the model group underwent a ligation of the left anterior descending branch. Subsequently, the two groups were compared by use of electrocardiography, heart function and histomorphology. The results have demonstrated that, after being improved, the ligation of the left anterior descending branch of coronary artery is a good method to establish the stable model of myocardial infarction. It can be applied to the research in mechanism and treatment of myocardial infarction.
Animals ; Coronary Vessels ; surgery ; Disease Models, Animal ; Ligation ; methods ; Male ; Myocardial Infarction ; etiology ; Random Allocation ; Rats ; Rats, Wistar

The present paper is to research the expression level of the mRNA of scavenger receptor class B type 1-receptor of high-density lipoprotein in endothelial cells after being treated by different shear stress. The second to fourth generations of the cultured human umbilical vein endothelial cells (HUVECs) were used in the experiment. The cells were divided into two groups. The first group was the control group which was not dealt with shear stress; the second group was the experimental group which concluded low shear stress group (4.2 dyne/cm2), moderate shear stress group (8.4 dyne/cm2) and high shear stress group (15 dyne/cm2). The load time was 1h, 2h, 4h and 8h, respectively. Harvesting the cells and extracting total RNA after being treated by different shear stresses, the expression level of the SR-B1 mRNA was detected by semi-quantitative RT-PCR technic. It was found that the expression of SR-B1 mRNA became weaker and weaker compared to the control group when it was stimulated continuously by the low shear stress, the lowest expression of SR-B1 mRNA appeared at 8h. In the moderate shear stress group, the expression of SR-B1 mRNA increased obviously. Compared to the control group, there was significant difference after being treated with 2h. In the high shear stress group, the expression of SR-B1 mRNA increased immediately when it was stimulated by the shear stress. And the expression of SR-B1 mRNA arrived peak value at 4h. Compared to the control group, there was significant difference after being treated for 1h. It was concluded that the harmful mechanism of the low shear stress is that it can increase the incidence of the atherosclerosis by reducing the reverse cholesterol transport and endothelial protection through decreasing the expression of the SR-B1. Otherwise, the high shear stress prevent the genesis of atherosclerosis by the contrary mechanism.
Atherosclerosis ; etiology ; Cells, Cultured ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; Humans ; RNA, Messenger ; genetics ; metabolism ; Scavenger Receptors, Class B ; genetics ; metabolism ; Stress, Mechanical

This paper reports the establishment of a model of turbulent flow separation area for experiment on the downstream of tubal stenosis, and adjust it to cooperate with the velocity and turbulent shear stress (TSS) detection by means of the particle image velocimetry (PIV), and with the pressure detection of pressure sensor in vitro. The velocity, TSS and wall pressure characteristics of the downstream of tubal stenosis were quantitatively detected and analyzed via the PIV and pressure sensor. And the hydrodynamic characteristics of the velocity, TSS and wall pressure in the flow separation area were primarily understood. The model can cooperate smoothly with the PIV and pressure sensor to detect the velocity, TSS and wall pressure; there exist low velocity, low TSS and low pressure in the flow separation area downstream of tubal stenosis.
Blood Flow Velocity ; physiology ; Computer Simulation ; Constriction, Pathologic ; physiopathology ; Heart Valve Diseases ; physiopathology ; Models, Cardiovascular ; Rheology ; Stress, Mechanical ; Vascular Diseases ; physiopathology