Abstract:Aim To study the diastolic effect and mechanism of farrerol on isolated pulmonary arteries of C57BL/6J mice. Methods After anesthesia, mouse lung tissue was quickly removed and placed into the 4 ℃ K-H buffer, pulmonary arteries were isolated under the microscope and cut into 2 mm long vascular rings for spare use. (1)The effect of farrerol on the resting tension of isolated mouse pulmonary arteries:in the resting state, the active mouse pulmonary artery rings were treated with different concentrations of farrerol (10－6,3×10－6,0－5,3×10－5 and 10－4 mol/L). (2)Farrerol relaxed mouse pulmonary artery experiment:pulmonary arteries were contracted using phenylephrine (PE, 1 μmol/L) or KCl (60 mmol/L), and when the contraction reached the platform, different concentrations of farrerol (10－6,3×10－6,0－5,3×10－5 and 10－4 mol/L) was added. (3) Farrerol inhibited pulmonary artery contraction experiment:under conditions with or without the addition of farrerol, pulmonary arteries were contracted using different concentrations of PE (10－9,3×10－9,0－8,3×10－8,0－7,3×10－7 and 10－6 mol/L) or KCl (0,0, 0,0, 80 and 120 mmol/L), and the pulmonary artery muscle tension was recorded. (4)Calcium free and recalcification experiments:under conditions with or without the addition of farrerol, the changes of isolated mouse pulmonary artery tension were measured in the state of calcium free or recalcification {2.5 mmol/L [Ca2＋]ex}. (5)The relationship between farrerol induced relaxation of isolated mouse pulmonary arteries and potassium ion channels:firstly, 60 mmol/L KCl solution was used to contract the mouse pulmonary arteries until the platform. Then, 3 mmol/L aminopyridine (4-AP), 2 mmol/L tetraethylammonium (TEA), 30 μmol/L BaCl2, and 10 μmol/L glibenclamide (Gli) were added and treated for 15 min. Subsequently, the pulmonary arteries were relaxed using a concentration gradient of farrerol. Results Farrerol had no significant effect on the mouse pulmonary arteries in the resting state, but had a concentration-dependent relaxing effect on the mouse pulmonary arteries pre-contracted with PE and KCl. While the pretreatment of 3×10－5 mol/L farrerol could significantly reduce the maximum contraction of mouse pulmonary arteries induced by PE and KCl (P＜0.01), as well as significantly reduce the contraction of mouse pulmonary arteries induced by KCl under calcium free or recalcification conditions (P＜0.01). Addition of the voltage-dependent potassium ion channel blocker 4-AP significantly reduced the maximum diastolic rate of mouse pulmonary arteries induced by farrerol (P＜0.01), while addition of the high conductivity calcium activated potassium ion channel blocker TEA, inward rectifying potassium ion channel blocker BaCl2, or ATP sensitive potassium ion channel blocker Gli had no significant effect on the vasodilation effect of farrerol (P＞0.05). ConclusionFarrerol has a relaxing effect on isolated mouse pulmonary arteries, and its mechanism may be related to open voltage-dependent potassium ion channels.

Abstract:Aim To study the protective effect of growth hormone releasing hormone receptor agonist MR409 on vascular calcification (VC) in gene deficient mice Db/Db diabetic mice (Db/Db mice). Methods With 12-week-old male wild-type (WT) C57BL/6 mice as the WT group (control group), 12-week-old male Db/Db mice were randomly divided into Db/Db group (diabetes group) and MR409 group (MR409 treatment group). MR409 group was given MR409 (15 μg/time) every other day for 8 weeks. At the end of the 8th week, the mouse serum alkaline phosphatase (ALP) and blood glucose levels were tested. HE staining was used to observe the morphological changes of aorta in mice. Calcium salt deposition in aorta was detected by von Kossa staining and alizarin red staining. Endothelium-dependent vasodilation function was measured by in vitro vascular perfusion system. Aortic calcification-related protein Runt-related transcription factor 2 (Runx2) protein expression was detected by immunohistochemical staining. Aortic reactive oxygen species (ROS) level was detected by dihydroethidium fluorescent staining. Results Compared with WT group, serum ALP activity increased, blood vessel wall thickness increased, vasodilation function decreased, and aortic ROS level increased in Db/Db group (P＜0.05). Compared with Db/Db group, ALP activity decreased, aortic hypertrophy decreased, vasodilation function improved, and ROS level of aorta decreased in MR409 group (P＜0.05). Compared with WT group, there was significant VC in Db/Db group, which showed increased calcium salt deposition and increased Runx2 protein expression in aorta (P＜0.05). Compared with Db/Db group, calcium salt deposition and Runx2 protein expression in aorta were decreased in MR409 group (P＜0.05). Conclusion MR409 can significantly inhibit VC, reduce aortic hypertrophy and improve vascular endothelial function in diabetic mice, and its mechanism may be related to the inhibition of the increase of Runx2 expression induced by oxidative stress.

Abstract:Aim To investigate the possible mechanisms by which high-density lipoprotein （HDL） lead to the development of atherosclerosis by analysing the properties changes of HDL from the patients with hypercholesterolemia and its influence on vascular function. Methods 20 patients （male11, female9, aged from 18 to 60 years old） with hypercholesterolemia were selected as hypercholesterolemia group and 20 healthy adults （male12, female8, aged from 18 to 60 years old） were chosen as control group. The plasma concentration of total cholesterol （TC）, triglyceride（TG）, low density lipoprotein cholesterol（LDLC） and high density lipoprotein cholesterol（HDLC） were measured. The inflammatory level of HDL was analyzed. HDL was isolated from the plasma and was incubated with the aortic of C57BL/6 mice to observe the vascular contraction and vasodilation. Results In patients with hypercholesterolemia, the plasma concentration of TC（6.49±0.76 mmol/L vs 4.67±0.34 mmol/L, P<0.05）, TG（3.16±1.85 mmol/L vs 1.27±0.53 mmol/L, P<0.05）, and LDLC（4.52±0.70 mmol/L vs 2.98±0.40 mmol/L, P<0.05） were significantly higher than that in healthy subjects. However, the plasma concentration of HDLC（1.28±0.41 mmol/L vs 1.16±0.23 mmol/L, P>0.05） had no significant difference between hypercholesterolemia group and control group. The inflammatory level of HDL in patients with hypercholesterolemia（RFU:1104.0±182.5 vs 366.2±84.5, P<0.05） was significantly increased compared with the controls. This proinflammatory HDL dramatically inhibited the endothelium-dependent vasodilation. Conclusions HDL in hypercholesterolemia not only turned to inflammatory states and lost its effect on protecting cardiovascular function, but impaired endothelium-dependent vasodilation. Proinflammatory HDL may be one of the key factors in promoting the formation of atherosclerosis.

Abstract:Aim To investigate the effects of chronic intrauterine hypoxia(CIH) on endothelium vascular relaxation and pathological change in adult offspring rabbit. Methods Sixteen New-Zealand rabbits were assigned randomly to two groups:CIH group (12%O2,n=8) and normal oxygen group (21%O2,n=8). After delivery,two male offspring rabbits per litter were selected and breast-fed for 3 months. Then they were randomly separated into high-fat diet and normal diet respectively. Thus 4 groups were got as follow:CIH with high fat diet (CIH+HFD,n=8),Non-CIH with high fat diet (NCIH+HFD,n=8),CIH with normal diet (CIH+ND,n=8) and normal control (n=8). At sixth months of age,offspring rabbits were evaluated for endothelium vascular relaxation of the abdominal aorta by ultrasonoscopy. Abdominal aorta was then taken out and observed by electron microscope and lightmicroscope. Results CIH could result in a series of effects in adult rabbit offspring,such as elevated serum total cholesterol (TC) and triglyceride (TG) level,and attenuated endothelial dependent vasodilation(EDV) of abdominal aorta (P<0.05). There were relevant pathological changes in different groups. All these influences caused by CIH were aggravated significantly when hyperlipemia was imposed (P<0.05). Conclusions CIH cause impaired EDV in adult offspring,which might serve as an important factor that can induce atherosclerosis. The adult offspring rabbit which have ever undergone chronic hypoxia in utero were more sensitive to the impairment of high-fat diet.

Abstract:Aim Discuss the relation between vascular endothelium function,body composition and glucose metabolism in middleaged patients with impaired glucose tolerance.Methods Adopt the Philips IU-22 color Doppler ultrasound diagnostic system to detect vascular endothelium function,body composition and glucose metabolism indexes,and process a statistic analysis.Result(1) The rate of impaired glucose tolerance group to catch coronary heart disease,the positive rate of diabetes family history and family history in cardiovascular disease,are all obviously higher than the normal glucose tolerance group.(2)Compared to the normal glucose tolerance group,the BMI,BF%,waist circumference and 2-hour postprandial blood glucose of the impaired glucose tolerance group show significant difference,while the WHR and Fasting blood glucose are obviously higher.There is no significant difference in the SBP and DBP between two groups.(3)There is significant difference in the brachial arterial Dia-P% between two groups,while the brachial arterial internal diameter and Dia-N% show no significant difference.(4)The Dia-P% of middleaged impaired glucose tolerance patients is related the OGTT2h blood glucose.(5) The multivariate successive regression equation of Dia-P% in the middleaged impaired glucose tolerance patients show a predictor variable:OGTT2h blood glucose.Conclusion Brachial arterial vasodilation dysfunction exists in the middleaged impaired glucose tolerance patients,and the indexes of body composition and glucose metabolism change.Meanwhile,the abnormality of insulin resistance and OGTT2h blood glucose play an important role in the brachial arterial vasodilation dysfunction of middleaged IGT patients.

Abstract:Aim To investigate difference of endothelium-dependent vasodilation or arterial elasticity in patients with different grade of coronary artery pathologic change.Methods Ninety six subjects were divided into four groups by results of coronary angiography:22 cases of normal coronary artery,20 cases of early coronary artery lesions,54 cases of coronary heart disease;coronary heart disease group was divided into two groups by the Gensini scoring:19 cases of gentle coronary artery lesions(Gensini score<20),35 cases of severe coronary artery lesions(Gensini score≥20).Flow-mediated dilation in the brachial artery was evaluated by ultrasound Doppler flow method.They were also underwent a noninvasive assessment of large artery and small artery elasticity index by using pulse wave analysis.Results The flow-mediated dilation of normal coronary artery,early coronary artery lesions,gentle coronary artery lesions,severe coronary artery lesions were 9.79%±4.33%,8.21%±4.38%,5.34%±3.67% and 4.59%±2.20% respectively.The large artery elasticity index of the four groups were 917.3±315.8,870.7±266.9,849.8±346.7,795.6±134.6 μL/Pa,respectively.The small artery elasticity index of the four groups were 5.05±2.01,4.68±1.43,4.02±2.10,3.23±1.81 mL/Pa respectively.The difference among the four groups was significant on flow-mediated dilation and small artery elasticity index(p<0.05).However,there was no significant difference among the four groups on large artery elasticity index.Conclusions Following the increase of grade of coronary artery pathologic change,the impaired endothelium-dependent vasodilation and reduced small artery elasticity index were worsened.The present study suggested that the measurement of flow-mediated dilation or small artery elasticity index might be used as a novel index for the determination of the pathological change grade of coronary artery.

Abstract:Aim To explore the relationship between brachial-ankle pulse wave(baPWV)and flow-mediated vasodilation(FMD)in patients with coronary heart disease(CHD).Methods 98 patients with CHD and 33 control subjects were recruited in the study.baPWV velocity was measured non-invasively using VP 1000 automated ABI/PWV analyzer.Flow-mediated vasodilation(FMD)in the brachial artery was measured by high-resolution ultrasound.Results FMD was significantly reduced in CHD patients compared with that in control subjects(5.4%±2.5% vs 11.1±4.4%,p<0.01);and baPWV was increased in CHD group as compared to the control group(1745.3±215.2 cm/s vs 1495.3±202.3 cm/s,p<0.01).There was a significant correlation between baPWV and FMD in patients with CHD(r=-0.70,p<0.001).Conclusions There were increased baPWV and impaired endothelial function in patients with CHD.The correlation between flow-mediated vasodilation and brachial-ankle pulse wave velocity was high.

Abstract:Aim To explore the influence of acute glucose loading on endothelium-dependent vasodilation in essential hypertension and the protective effect of vitamin C and vitamin E. Methods 39 patients with essential hypertension (EH) and 21 normaltensive controls were randomly divided into three groups. We evaluated the acute effects of oral glucose loading(75 g) alone, with Vitamin C (2 g) and E (0.8 g) or Vitamin C (0.9 g) on endothelium-dependent flow-mediated dilation (EDF) of the brachial artery assessed by high-resolution ultrasound technique on 0,1,2,3 hour after glucose loading respectively. At the same time, we measured the concentrations of plasma superoxide dismutase (SOD), total antioxidative capacity (T-AOC) and superoxide anion (O 2 -). Results The basic EDF were diminished in EH. After 75 g glucose loading, EDF were decreased significantly in both patients (9.48%±3.33% vs 13.09%±6.78%, p<0.05) and controls (14.20%±6.48% vs 17.91%±6.87%, p<0.05). The severity of postprandial EDF was more serious in EH than in controls groups (9.48%±3.33% vs 14.20%±6.48%, p<0.05). The impairment was most significant in the first hour and returned to the basic level in the second hour. Different dose of vitamins can improve the impairment in a dose-dependent manner. Conclusions EDF impairment was induced by acute hyperglycemia in EH patients which can be reversed by high concentration of vitamin C and vitamin E.

Abstract:Aim To study the changes in endothelium dependent vasodilation function,serum nitric oxide (NO) and superoxide dismutase (SOD) and their inter relationships in patients with essential hypertension (EH). Methods High resolution B mode ultrasonography was used to measure the endothelial dependent vasodilation in 28 patients with EH and 28 matched healthy subjects. Serum levels of NO and SOD were also measured. Results The increased percentage of the brachial artery diameter after reactive hyperemia was lower in patients with EH than that of normal controls (6.33%±2.59% vs 13.14%±4.24% p<0.001), whereas nitroglycerin induced changes were similar (p>0.05). Serum levels of NO,SOD in patients with EH was significantly lower compared with those in controls (53.55±23.5 μmol/L vs 83.26±23.25 μmol/L,86.57±26.66 kNU/L vs 117.1±33.64 kNU/L,p<0.001). Correlation analysis shows that endothelium dependent vasodilation function was negatively correlated with ages,systolic blood pressure,dilated blood pressure,the coefficients were -0.366 (p<0.01),-0.65 (p<0.001),-0.672 (p<0.001),and was positively correlated with serum NO and SOD,the coefficients were 0.838 (p<0.001),0.683 (p<0.001). The analysis of multiple stepwise regression shows that the endothelium dependent vasodilation function was negatively correlated with dilated blood pressure and positively correlated with serum NO and SOD. Conclusion Our findings support that endothelium vasodilation is impaired and was correlated with reduction of NO and increase of active oxygen species.

Abstract:Aim To assess the extent of atherosclerosis in elderly hypertensive patients. Methods With high resolution ultrasound, not only intima-media thickness (IMT), plaque of carotid arteries, but also endothelium-dependent relaxing function were measured in 82 subjects, consisted of 62 patients with essential hypertension and 20 controls. Results IMTs of carotid arteries were higher in hypertensive patients than those in normal subjects (P<0.05). There was an increasing trend for IMT with the severity of plaque. Flow mediated dialtation in the groups with essential hypertension was much reduced compared with the control group (P<0.05). Conclusions Increases in IMT of carotid arteries and impairment of endothelium-dependent vasolidation are related to atherosclerosis in early stage in elderly hypertensive patients.