Phosphorylated PKM2 regulates endothelium-dependent vasodilation in diabetes / 中南大学学报(医学版)

OBJECTIVES@#Endothelium-dependent vasodilation dysfunction is the pathological basis of diabetic macroangiopathy. The utilization and adaptation of endothelial cells to high glucose determine the functional status of endothelial cells. Glycolysis pathway is the major energy source for endothelial cells. Abnormal glycolysis plays an important role in endothelium-dependent vasodilation dysfunction induced by high glucose. Pyruvate kinase isozyme type M2 (PKM2) is one of key enzymes in glycolysis pathway, phosphorylation of PKM2 can reduce the activity of pyruvate kinase and affect the glycolysis process of glucose. TEPP-46 can stabilize PKM2 in its tetramer form, reducing its dimer formation and phosphorylation. Using TEPP-46 as a tool drug to inhibit PKM2 phosphorylation, this study aims to explore the impact and potential mechanism of phosphorylated PKM2 (p-PKM2) on endothelial dependent vasodilation function in high glucose, and to provide a theoretical basis for finding new intervention targets for diabetic macroangiopathy.@*METHODS@#The mice were divided into 3 groups: a wild-type (WT) group (a control group, C57BL/6 mice) and a db/db group (a diabetic group, db/db mice), which were treated with the sodium carboxymethyl cellulose solution (solvent) by gavage once a day, and a TEPP-46 group (a treatment group, db/db mice+TEPP-46), which was gavaged with TEPP-46 (30 mg/kg) and sodium carboxymethyl cellulose solution once a day. After 12 weeks of treatment, the levels of p-PKM2 and PKM2 protein in thoracic aortas, plasma nitric oxide (NO) level and endothelium-dependent vasodilation function of thoracic aortas were detected. High glucose (30 mmol/L) with or without TEPP-46 (10 μmol/L), mannitol incubating human umbilical vein endothelial cells (HUVECs) for 72 hours, respectively. The level of NO in supernatant, the content of NO in cells, and the levels of p-PKM2 and PKM2 protein were detected. Finally, the effect of TEPP-46 on endothelial nitric oxide synthase (eNOS) phosphorylation was detected at the cellular and animal levels.@*RESULTS@#Compared with the control group, the levels of p-PKM2 in thoracic aortas of the diabetic group increased (P<0.05). The responsiveness of thoracic aortas in the diabetic group to acetylcholine (ACh) was 47% lower than that in the control group (P<0.05), and that in TEPP-46 treatment group was 28% higher than that in the diabetic group (P<0.05), while there was no statistically significant difference in the responsiveness of thoracic aortas to sodium nitroprusside (SNP). Compared with the control group, the plasma NO level of mice decreased in the diabetic group, while compared with the diabetic group, the phosphorylation of PKM2 in thoracic aortas decreased and the plasma NO level increased in the TEPP-46 group (both P<0.05). High glucose instead of mannitol induced the increase of PKM2 phosphorylation in HUVECs and reduced the level of NO in supernatant (both P<0.05). HUVECs incubated with TEPP-46 and high glucose reversed the reduction of NO production and secretion induced by high glucose while inhibiting PKM2 phosphorylation (both P<0.05). At the cellular and animal levels, TEPP-46 reversed the decrease of eNOS (ser1177) phosphorylation induced by high glucose (both P<0.05).@*CONCLUSIONS@#p-PKM2 may be involved in the process of endothelium-dependent vasodilation dysfunction in Type 2 diabetes by inhibiting p-eNOS (ser1177)/NO pathway.

Effect of Physical Training on Nitric Oxide Levels in Patients with Arterial Hypertension: An Integrative Review

Abstract The regular practice of physical exercise as a non-pharmacological treatment of arterial hypertension (AH) has been encouraged due to causing a series of physiological responses in the cardiovascular system, such as the production of vasoactive substances, including nitric oxide (NO). NO is a relaxation factor released by the endothelium, and the decrease in its bioavailability is related to coronary and arterial diseases, such as AH. This study aimed to perform an integrative literature review to elucidate the effect of physical training on NO levels in patients with AH and to establish a relationship between these levels and blood pressure (BP) control. A literature review was was performed by searching PubMed / MEDLINE, Lilacs, Scielo, Cinahl and Embase databases. The search string used was ("arterial hypertension" OR hypertension) AND (exercise OR "physical exercise" OR "aerobic exercise" OR "exercise training" or "physical activity") AND ("nitric oxide"). We included fully available controlled and uncontrolled clinical trials published in English and Portuguese languages in the last 10 years. The review consisted of 16 articles, of which 13 reported an increase in NO production after the physical training intervention, and three studies found no change. In addition, 15 studies observed a reduction in BP after the intervention. In conclusion, regular practice of physical exercises, advocating moderate intensity, can improve NO bioavailability in pre-hypertensive and hypertensive individuals, which seems to be one of the mechanisms responsible for BP reduction.

Global endothelial function assessment using pulse wave analysis in hypercholesterolemia

To compare global endothelial function assessed by pulse wave analysis (PWA) using the ratio of endothelium dependent vasodilatation (EDV) to endothelium independent vasodilatation (EIV) in patients with hypercholesterolemia and controls. 92 subjects [46 hypercholesterolemics, 46 controls] were studied at standardized conditions. Baseline augmentation index (AIx) was assessed followed by the administration of 0.5 mg sublingual nitroglycerine, an endothelium independent vasodilator. AIx was assessed and the maximum change in AIx after nitroglycerine was recorded as EIV. After a washout period of 30 minutes, 400 µg of inhaled salbutamol, an endothelium dependent vasodilator was administered. AIx was assessed again and the maximum change in AIx after salbutamol was recorded as EDV. Global endothelial function was calculated as EDV:EIV ratio. EDV and EIV in patients with hypercholesterolemia compared to controls were 2.97 ± 3.95 and 6.65 ± 3.80 (p<0.001); and 13.41 ± 4.57 and 15.88 ± 4.78 (p=0.01) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls; 0.21 ± 0.38 and 0.44 ± 0.24 (p<0.001) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls. PWA is a potential clinical tool to assess global endothelial function in patients with hypercholesterole

Antioxidative Propolis From Stingless Bees (Heterotrigona Itama) Preserves Endothelium-Dependent Aortic Relaxation of Diabetic Rats: The Role of Nitric Oxide and Cyclic Guanosine Monophosphate

Propolis from stingless bees (Heterotrigona itama) is a resinous compound that exhibits antihyperglycaemia, free radical scavenging, and cardioprotective properties. The effect of propolis on diabetic vessels has not been investigated. Thus, this research aimed to determine the effect of propolis supplementation on the level of antioxidants and its mechanism of action in the aorta of diabetic rats. Male Sprague-Dawley rats were divided into five groups (n=8/group): healthy (control), untreated diabetes (DM), metformin-treated diabetes (DM+M, 300 mg/kg/day metformin), propolis-treated diabetes (DM+P, 300 mg/kg/day propolis extract) and diabetes with combined treatment (DM+M+P, dosage as former). Oral supplementation was conducted for four weeks immediately upon successful induction of diabetes by streptozotocin (60 mg/kg, intraperitoneal injection). At the end of the study, the rats were euthanised, and thoracic aorta was processed into tissue homogenates to determine the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase-1 (GPx-1) and soluble receptor for advanced glycation end-products (sRAGE). Aorta segments were harvested to examine their relaxation response towards graded concentration of acetylcholine (Ach; 10-8-10-4) M following precontraction with phenylephrine (PE; 10-6 M). Vasorelaxation towards a cumulative dose of propolis (0.01-1.00%) using PE-precontracted healthy aorta (n=6/experiments) was investigated under various simulated conditions: physiological buffer, L-NAME (10-4 M), methylene blue (10-5 M), indomethacin (10-5 M) and elevated glucose (25 mM). Propolis maintained antioxidative enzymes and sRAGE decoy molecules in the aortic tissue of the diabetic rats. The amelioration of diabetes-induced impairment of endothelium-dependent relaxation by propolis was mediated through the nitric oxide(NO)-cyclic guanosine monophosphate (cGMP) pathway. This non-clinical study reports vasoprotective property of propolis in diabetes mellitus.

Diámetro basal de la arteria braquial en la evaluación del paciente con hipertensión esencial / Basal diameter of brachial artery when assessing patients with essential hypertension

Introducción: Las enfermedades cardiovasculares de mayor prevalencia y la hipertensión arterial tienen como sustento la aterosclerosis y la disfunción endotelial. La evaluación no invasiva de aterosclerosis subclínica constituye un complemento para la estratificación del riesgo cardiovascular en la evaluación del paciente hipertenso. Objetivo: Determinar la utilidad del diámetro basal de la arteria braquial en la evaluación del paciente con hipertensión arterial esencial. Método: Se realizó un estudio transversal analítico que incluyó 30 pacientes con hipertensión arterial esencial, a quienes se les realizó ultrasonografía para medir el diámetro basal de la arteria braquial, la vasorreactividad dependiente del endotelio y el grosor íntima media carotídeo, así como se precisó su riesgo cardiovascular, el tiempo de evolución y grado de la hipertensión arterial. Para determinar la asociación entre el diámetro arterial y el resto de las variables se utilizaron pruebas estadísticas como ANOVA de una vía y el coeficiente de correlación de Pearson. Resultados: La disfunción endotelial estuvo presente en 83,3 por ciento de los pacientes estudiados. Tanto el grosor del complejo íntima media carotídeo como la vasorreactividad dependiente del endotelio fueron adecuados marcadores de la enfermedad aterosclerótica. El diámetro basal de la arteria braquial tuvo una correlación inversa con la vasorreactividad dependiente del endotelio, y mostró valores medios esperados en relación a la presencia del tabaquismo, y con los peores grados de la enfermedad hipertensiva y el riesgo cardiovascular. Conclusiones: El diámetro basal de la arteria braquial no mostró la asociación esperada para la evaluación del paciente hipertenso esencial en la población estudiada(AU)

Introduction: The most prevalent cardiovascular diseases and high blood pressure are supported by atherosclerosis and endothelial dysfunction. The non-invasive assessment of subclinical atherosclerosis complements the cardiovascular risk stratification when evaluating hypertensive patients. Objective: To determine the value of the basal diameter of the brachial artery in assessing patients suffering from essential arterial hypertension. Method: An analytical cross-sectional study was carried out in 30 patients with essential arterial hypertension. They underwent ultrasonography to measure the basal diameter of the brachial artery, endothelium-dependent vasoreactivity and carotid mean intima thickness, as well as the cardiovascular risk, time of evolution and degree of arterial hypertension. Statistical tests such as one-way ANOVA and Pearson's correlation coefficient were used to determine the association between arterial diameter and the rest of the variables. Results: Endothelial dysfunction was present in 83.3% of the studied patients. Both the thickness of the carotid media intima complex and endothelium-dependent vasoreactivity were adequate markers for atherosclerotic disease. The basal diameter of the brachial artery had inverse correlation with endothelium-dependent vasoreactivity, and it showed expected mean values in relation to the presence of smoking, and with the worst degrees of hypertensive disease and cardiovascular risk. Conclusions: The basal diameter of the brachial artery did not show the expected association for the evaluation of essential hypertensive patients in the studied population(AU)

Inhibition Effect of TLR4mAb on mmLDL Impaired Endothelium-dependent Vasodilatation in Mouse Mesenteric Artery / 中国药学杂志

OBJECTIVE: To investigate the effect and mechanism of TLR4 monoclonal antibody (TLR4mAb) on mmLDL induced impairment of endothelium-dependent vasodilatation in mouse mesenteric artery. METHODS: The experiment established three groups of normal saline group, mmLDL treatment group and TLR4mAb intervention group. The concentration of IL-1β and TNF-α in plasma was determined by enzyme-linked immunosorbent assay (ELISA). Measurement of endothelium-dependent vasodilatation was achieved by microvascular tension mapping. Western blot and RT-PCR were used to investigate the expression level of protein and mRNA expressions in vascular tissues. In addition, ultra-structure of mesenteric artery endothelial cells was observed by transmission electron microscope. RESULTS: TLR4mAb could improve the damage of mmLDL induced impairment of endothelium-dependent vasodilatation in a dose-dependent manner. Besides, TLR4mAb obviously up-regulated protein expressions in KCa3.1-channel and KCa2.3-channel, and down-regulated the expression of inflammatory factors TNF-α and IL-1β. Furthermore, the improvement of mmLDL impaired vascular endothelial cells and endothelium-dependent vasodilatation might be correlated with its competitive antagonism of mmLDL-activated TLR4 signal transduction pathway and its downstream NF-κBp65 and p-38 MAPK pathway. CONCLUSION: Administration of TLR4mAb in advance can alleviate the impairment of endothelial cells and the decrease of endothelium-dependent vasodilatation induced by mmLDL, and inhibit the overexpression of inflammatory factors. Regulation of TLR4 pathway as well as its downstream NF-κBp65 and P-38 MAPK pathways may be effective targets for the prevention and treatment of cardiovascular diseases.

Knockdown of transglutaminase-2 prevents early age-induced vascular changes in mice

Abstract Purpose: To determine whether the absence of transglutaminase 2 enzyme (TG2) in TG2 knockout mice (TG2-/-) protect them against early age-related functional and histological arterial changes. Methods: Pulse wave velocity (PWV) was measured using non-invasive Doppler and mean arterial pressure (MAP) was measured in awake mice using tail-cuff system. Thoracic aortas were excised for evaluation of endothelial dependent vasodilation (EDV) by wire myography, as well as histological analyses. Results: PWV and MAP were similar in TG2-/-mice to age-matched wild type (WT) control mice. Old WT mice exhibited a markedly attenuated EDV as compared to young WT animals. The TG2-/-young and old mice had enhanced EDV responses (p<0.01) as compared to WT mice. There was a significant increase in TG2 crosslinks by IHC in WT old group compared to Young, with no stain in the TG2-/-animals. Optical microscopy examination of Old WT mice aorta showed thinning and fragmentation of elastic laminae. Young WT mice, old and young TG2-/-mice presented regularly arranged and parallel elastic laminae of the tunica media. Conclusion: The genetic suppression of TG2 delays the age-induced endothelial dysfunction and histological modifications.

Antihypertensive efficacy of extract of Hedera helix in high salt-induced hypertensive Sprague-Dawley rats

Objective:To explore the antihypertensive effect of extracts from the leaves of Hedera helix (H. helix) on normotensive and hypertensive rats in-vivo followed by vasodilatory studies in-vitro.Methods:The crude methanolic extract was prepared and the activity directed fractionation was carried out. Spectrophotometric analysis of total phenolic and flavonoid content was also done. HPLC analysis was performed for the detection of hederacoside C. In-vivo blood pressure study was carried out in normotensive and high salt-induced hypertensive Sprague-Dawley rats. Isolated aortic tissues from rat and rabbit were used for in-vitro studies. The effects were recorded and analyzed through PowerLab data acquisition system.Results:Crude extract of H. helix (1-30 mg/kg) decreased blood pressure to greater extent in high salt-induced hypertensive rats in-vivo compared to the normotensive [Max. fall (58.59±0.02) mmHg vs. (67.53±3.07) mmHg]. The n-hexane, chloroform, ethyl acetate and aqueous fractions were also checked. These fractions were more effective in hypertensive rats. Aqueous fraction was more potent and n-hexane the least. In isolated rat aortic rings precontracted with phenylephrine, crude extract induced endothelium-dependent effect. The endothelium-dependent component of vasodilatory effect was ablated with L-NAME, and denudation of endothelium. The aqueous fraction was most potent vasodilator. In aortic rings from hypertensive rats, extract and fractions produced partial endothelium-independent effect which was not affected by pretreatment with L-NAME, indicating endothelium dysfunction in the hypertensive rats and suggesting additional vasodilatory mechanisms. In rabbit aorta, the extract and fractions also inhibited phenylephrine and high KConclusions:Our findings indicate that extract and fractions of H. helix are antihypertensive remedies, which is the outcome of vasodilatory effect. This vasodilatory effect is mediated through nitric oxide and Ca

Potentiation of endothelium-dependent vasorelaxation of mesenteric arteries from spontaneously hypertensive rats by gemigliptin, a dipeptidyl peptidase-4 inhibitor class of anti-diabetic drug

Dipeptidyl peptidase4 (DPP4) inhibitors such as gemigliptin are anti-diabetic drugs elevating plasma concentration of incretins such as GLP-1. In addition to the DPP4 inhibition, gemigliptin might directly improve the functions of vessels under pathological conditions. To test this hypothesis, we investigated whether the acetylcholine-induced endothelium dependent relaxation (ACh-EDR) of mesenteric arteries (MA) are altered by gemigliptin pretreatment in Spontaneous Hypertensive Rats (SHR) and in Wistar-Kyoto rats (WKY) under hyperglycemia-like conditions (HG; 2 hr incubation with 50 mM glucose). ACh-EDR of WKY was reduced by the HG condition, which was significantly recovered by 1 µM gemigliptin while not by saxagliptin and sitagliptin up to 10 µM. The ACh-EDR of SHR MA was also improved by 1 µM gemigliptin while similar recovery was observed with higher concentration (10 µM) of saxagliptin and sitagliptin. The facilitation of ACh-EDR by gemigliptin in SHR was not observed under pretreatment with NOS inhibitor, L-NAME. In the endotheliumdenuded MA of SHR, sodium nitroprusside induced dose-dependent relaxation was not affected by gemigliptin. The ACh-EDR in WKY was decreased by treatment with 30 µM pyrogallol, a superoxide generator, which was not prevented by gemigliptin. Exendin-4, a GLP-1 analogue, could not enhance the ACh-EDR in SHR MA. The present results of ex vivo study suggest that gemigliptin enhances the NOS-mediated EDR of the HG-treated MA as well as the MA from SHR via GLP-1 receptor independent mechanism.

Antihypertensive efficacy of extract of Hedera helix in high salt-induced hypertensive Sprague-Dawley rats

Objective: To explore the antihypertensive effect of extracts from the leaves of Hedera helix (H. helix) on normotensive and hypertensive rats in-vivo followed by vasodilatory studies in-vitro. Methods: The crude methanolic extract was prepared and the activity directed fractionation was carried out. Spectrophotometric analysis of total phenolic and flavonoid content was also done. HPLC analysis was performed for the detection of hederacoside C. In-vivo blood pressure study was carried out in normotensive and high salt-induced hypertensive Sprague-Dawley rats. Isolated aortic tissues from rat and rabbit were used for in-vitro studies. The effects were recorded and analyzed through PowerLab data acquisition system. Results: Crude extract of H. helix (1-30 mg/kg) decreased blood pressure to greater extent in high salt-induced hypertensive rats in-vivo compared to the normotensive [Max. fall (58.59±0.02) mmHg vs. (67.53±3.07) mmHg]. The n-hexane, chloroform, ethyl acetate and aqueous fractions were also checked. These fractions were more effective in hypertensive rats. Aqueous fraction was more potent and n-hexane the least. In isolated rat aortic rings precontracted with phenylephrine, crude extract induced endothelium-dependent effect. The endothelium-dependent component of vasodilatory effect was ablated with L-NAME, and denudation of endothelium. The aqueous fraction was most potent vasodilator. In aortic rings from hypertensive rats, extract and fractions produced partial endothelium-independent effect which was not affected by pretreatment with L-NAME, indicating endothelium dysfunction in the hypertensive rats and suggesting additional vasodilatory mechanisms. In rabbit aorta, the extract and fractions also inhibited phenylephrine and high K

Application of fingertip photoplethysmogram assessment of endothelial function in screening coronary heart disease patients / 吉林大学学报(医学版)

Objective:To investigate the application of photoplethysmogram in analyzing the fingertip pulse amplitude volume (PAV)to evaluate the endothelial function in diagnosing coronary heart disease,and to clarify its relationship with the risk factors of cardiovascular diseases.Methods:Total 409 patients with chest pain accepted coronary angiography (CAG)were selected and diveded into positive group (CAG+)(n=288)and negative group (CAG-) (n = 121)according to angiographic results.Fingertip photoplethysmogram was used to analyze the fingertip PAV by the way of applying endothelial function diagnostic after reactive ischemia,and the relationship between the PAV value and the risk factors of coronary heart diseases was analyzed,and the critical reference value of prediction index of coronary heart disease was determined.The risk factors such as age,gender,serum total cholesterol (TC ), low density lipoprotein (LDL ), high density lipoprotein (HDL ), non-HDL, serum triglyceride (TG),hypertension,diabetes,smoking,family history of coronary heart disease,body mass index (BMI)of the subjects in various groups were analyzed,and the relationship between the risk factors of coronary heart disease and PAV was analyzed by Logistic regression analysis.Results:The PAV of patients in CAG+group was significantly lower than that in CAG-group (P <0.01).The peak point of PAV was<1.37,if PAV<1.37 was used to predict the coronary heart disease,the predictive sensitivity,the specificity,the positive prediction and the negative prediction were 74.65%,44.63%, 76.24%, and 42.52%.The Logistic regression analysis showed that PAV was negatively associated with hypertension,smoking history,TG (OR= 1.476,OR=2.002, OR = 1.844;P < 0.01 ). Conclusion: PAV is associated with coronary heart disease and its risk factors (hypertension,smoking history,TG),and PAV=1.37 can be used as the peak point to predict the coronary heart disease.

Protective effect of growth differentiation factor 11 on aorta in ApoE-/-mice fed with high-fat diet / 中华内分泌代谢杂志

Objective To investigate the effect of growth differentiation factor 11 ( GDF11 ) on aorta in apolipoprotein E-Null( ApoE-/-) mice and its possible mechanisms. Methods Four-week-old healthy male ApoE-/-mice were fed with high-fat diet for 1 week and were then divided into 4 groups:vehicle group(n=10), GDF11 group (n=10),adeno-associated virus-green fluorescent protein group(AAV-GFP group, n=10), and AAV-GDF11 group ( n=10 ) . The mice received intraperitoneal injection with phosphate buffered saline, GDF11 protein, a single injection of purified AAV-GDF11 or AAV-GFP through the tail vein, respectively. After 4 weeks, serum GDF11/8 level and endothelium-dependent vasodilatation were detected. After 12 weeks, serum GDF11/8, interleukin-6 (IL-6), tumor necrosis factor-α( TNF-α), total cholesterol ( TC), triglycerides ( TG), oxidized low density lipoprotein(ox-LDL), and free fatty acids(FFA)levels were measured, the plaque areas in aortic enface and cross sections were measured by oil red O or HE staining, the macrophages/T lymphocytes infiltration in plaques were detected with immunohistochemistry, and the mRNA expressions of IL-6, TNF-α, and IL-10 were determined by real-time PCR. Results Compared with vehicle or AAV-GFP groups, GDF11 and AAV-GDF11 groups presented improved endothelium-dependent vasodilatation, decreased levels of blood inflammatory factors, blood lipid, reduced plaque on face area sections[Vehicle group : GDF11 group:(31. 23 ± 3. 12)% vs (17. 18 ± 2. 17) %;AAV-GFP group : AAV-GDF11 group:(38.01±4.43)% vs(14.54±2.86)%,P<0.05]andcrosssections[Vehiclegroup :GDF11 group:(19. 87 ± 2. 11)% vs (10. 32 ± 1. 47)%;AAV-GFP group : AAV-GDF11 group:(23. 02 ± 2. 76)%vs (9.06±1.63)%, P<0. 05]. There were less macrophages and T lymphocytes infiltration in plaques and lower mRNA expressions of inflammatory factors at aortic wall. Conclusion GDF11 reduces the area of atherosclerotic lesion in ApoE-/-mice, which may be involved in endothelial protection, such as to reduce inflammatory reaction, and to change cellular composition in plaques.

Endothelial-dependent Vasodilatation and Expressions of CyPA, p-ERK1/2 in Experimental Rats With Obesity Combining Atherosclerosis / 中国循环杂志

Objective: To observe the endothelial-dependent vasodilatation and expressions of cyclophilin A (CyPA), phosphorylated extracellular signal regulated kinase1/2 (p-ERK1/2) in experimental rats with obesity combining atherosclerosis. Methods: A total of 30 male Wistar rats were randomly divided into 3 groups:Control group, the rats received basic diet followed by intraperitoneal injection of normal saline;Atherosclerosis (AS) group, the rats received basic diet for 8 weeks followed by high cholesterol diet with intraperitoneal injection of a single dose vitamin D3 600,000 IU/kg; Obesity+AS group, the rats received high cholesterol diet for 8 weeks (which made their body weights at 20%higher than the other 2 groups) followed by intraperitoneal injection of a single dose vitamin D3 600,000 IU/kg. n=10 in each group. 16 weeks later, the endothelial-dependent vasodilatation was examined in all rats, expressions of CyPA and p-ERK1/2 in arterial wall were detected by HE staining and immunohistochemistry. Results: Compared with Control group, both AS group and Obesity+AS group had reduced endothelial-dependent vasodilatation (72.49 ± 3.27)%and (42.28 ± 2.62)%vs (96.63 ± 3.85)%, such reduction was even more in Obesity+AS group (42.28 ± 2.62)%vs (72.49 ± 3.27)%, all P Conclusion: The rats with obesity and AS had decreased endothelial-dependent vasodilatation, severe atherosclerosis and calciifcation plaques, increased expressions of CyPA and p-ERK1/2, which speculated that obesity might be an independent risk factor for atherosclerosis.

Role of Endothelium-Dependent Hyperpolarisation and Prostacyclin in Diabetes

The endothelium plays a crucial role in maintaining vascular homeostasis by producing several vasodilating factors, including nitric oxide (NO), prostacyclin (PGI2), and endothelium-dependent hyperpolarisation (EDH); however, the balance between endothelial relaxing and contracting factors is disrupted in disease states such as diabetes mellitus and hypertension. Most reported studies of endothelial dysfunction in diabetes focused on the actions of NO; however, there is accumulating evidence demonstrating that in addition to NO, PGI2 and EDH are likely to contribute to the vasodilatation of blood vessels. EDH plays an important role as a regulator of vascular tone and reactivity in resistance and conduit arteries of animal models and humans. PGI2 only plays a minimal role in endothelium-dependent vasodilatation but may serve as an important compensatory mechanism in conditions in which NO and EDH activities are decreased. Further studies are needed to determine the exact roles of EDH and PGI2 in the development of endothelial dysfunction and clinical vasculopathy in humans with type 1 and type 2 diabetes.

Scutellarin attenuates endothelium-dependent aasodilation impairment induced by hypoxia reoxygenation, through regulating the PKG signaling pathway in rat coronary artery / 中国天然药物

Scutellarin (SCU), a flavonoid from a traditional Chinese medicinal plant. Our previous study has demonstrated that SCU relaxes mouse aortic arteries mainly in an endothelium-depend-ent manner. In the present study, we investigated the vasoprotective effects of SCU against HR-induced endothelial dysfunction (ED) in isolated rat CA and the possible mechanisms involving cyclic guanosine monophosphate (cGMP) dependent protein kinase (PKG). The isolated endothelium-intact and endothelium-denuded rat CA rings were treated with HR injury. Evaluation of endothelium-dependent and -independent vasodilation relaxation of the CA rings were performed using wire myography and the protein expressions were assayed by Western blotting. SCU (10-1 000 μmol·L(-1)) could relax the endothelium-intact CA rings but not endothelium-denuded ones. In the intact CA rings, the PKG inhibitor, Rp-8-Br-cGMPS (PKGI-rp, 4 μmol·L(-1)), significantly blocked SCU (10-1 000 μmol·L(-1))-induced relaxation. The NO synthase (NOS) inhibitor, NO-nitro-L-arginine methylester (L-NAME, 100 μmol·L(-1)), did not significantly change the effects of SCU (10-1 000 μmol·L(-1)). HR treatment significantly impaired ACh-induced relaxation, which was reversed by pre-incubation with SCU (500 μmol·L(-1)), while HR treatment did not altered NTG-induced vasodilation. PKGI-rp (4 μmol·L(-1)) blocked the protective effects of SCU in HR-treated CA rings. Additionally, HR treatment reduced phosphorylated vasodilator-stimulated phosphoprotein (p-VASP, phosphorylated product of PKG), which was reversed by SCU pre-incubation, suggesting that SCU activated PKG phosphorylation against HR injury. SCU induces CA vasodilation in an endothelium-dependent manner to and repairs HR-induced impairment via activation of PKG signaling pathway.

Effect of Jia-jian-yi-yin decoction on endothelial dysfunction in ovariecto-mized female rats / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the effect of Jia-jian-yi-yin decoction on endothelium-dysfunction in ovariecto-mized rats.METHODS:The ovariectomized rats were treated with Jia-jian-yi-yin decoction or turbid liquid of estradiol va-lerate for 8 weeks.The vascular ring tension was measured.Scanning electron microscopy and Western blotting were ap-plied to assess the function of endothelium-dependent dilation, aortic endothelial morphology and the expression of endothe-lial lipase.The pathologic sections were prepared to observe the effect of Jia-jian-yi-yin decoction on the uterus.RE-SULTS:In ovariectomized rats, the decrease in endothelium-dependent relaxation to acetylcholine ( ACh) was reversed to normal level, the endothelial morphology returned to normal without lipid accumulation and the endothelial lipase expression was decreased by Jia-jian-yi-yin decoction.Furthermore, no obvious change of the wet weight of uterine between the ovari-ectomized rats with or without Jia-jian-yi-yin decoction treatment was observed.CONCLUSION:Jia-jian-yi-yin decoction may have protective effects on endothelium-dependent vasodilation and aortic endothelial morphology in estrogen-deficient animals.

Effect of different doses of rosuvastatin on brachial artery endothelium-dependent vasodilation and carotid intima-media thickness in patients with coronary heart disease / 中国生化药物杂志

Objective To investigate effect of different doses of rosuvastatin on brachial artery endothelium-dependent vasodilation and carotid intima-media thickness in patients with coronary heart disease.Methods 92 patients with coronary heart disease in our hospital were admitted and divided into four groups according to randomly digital method, including 23 cases in control group were treated with lipid nitrate, antiplatelet aggregation, anticoagulant, lowering blood sugar, blood pressure control and other of conventional therapy;23 cases in group A, on the basis of conventional therapy, were treated with rosuvastatin 5 mg/d, orally, once daily;23 cases in group B were treated with rosuvastatin 10 mg/d, orally, once daily based on the conventional therapy;23 cases in group C were treated with rosuvastatin 20 mg/d, orally, once daily based on conventional treatment, each group was treated for 8 weeks.Brachial artery endothelium-dependent vasodilation (FMD) and carotid intima-media thickness (IMT) of patients before and after treatment were collected by color ultrasonic doppler, while observed lipid levels changes of 4 groups.Results Control group was treated for eight weeks, FMD, ITM, blood lipid levels and each index values were not significantly changed, the difference was not statistically significant;After treatment, total cholesterol ( TC) , low-density lipoprotein cholesterol C ( LDL-C) of A, B, C groups were significantly better than that before treatment, the difference was statistically significant (P<0.05), and decrease amplitude with dose of rosuvastatin increased became grearer, but the total cholesterol (TC), high density lipoprotein cholesterol C( HDL-C) there was no significant difference compared with before treatment; Compared with before treatment, ITM of A, B, C groups decreased, and the difference was statistically significant (P<0.05), decrease amplitude with dose of rosuvastatin increased became greater.Conclusion Rosuvastatin can significantly improve brachial artery endothelium-dependent vasodilation and carotid intima-media thickness in patients with coronary heart disease, and there is a clear dose-response relationship, which may be associated with rosuvastatin decrease total cholesterol and low-density lipoprotein cholesterol C in patients with coronary heart disease.It has guide significance to clinical.

Protection of puerarin on impaired vascular endothelial function induced by glycosylated protein / 中国药学杂志

OBJECTIVE: To investigate the effects of puerarin on impaired endothelium-dependent relaxation induced by glycosylated bovine serum albumin (GBSA) in rabbit thoracic aorta and its mechanisms. METHODS: The rings were incubated with GBSA for 30 min to induce endothelial dysfunction, and with puerarin(0.25, 0.5 and 1 g · L-1), A-nitro-L-arginine methyl ester (L-NAME, 30 νmol · L-1), and indomethacin(10 μmol · L-1) to investigate the protective effect of puerarin on impaired vascular endothelial function elicited by GBSA, and the effect of L-NAME and indomethacin on the protective effect of puerarin. Moreover, the content of nitric oxide (NO) and malonaldehyde (MDA) and the activity of superoxide dismutase(SOD) in the rings were measured. RESULTS: Exposure of aortic rings to GBSA (200 mg · L-1) for 30 min resulted in a significant inhibition of endothelium-dependent relaxation, but had no affect on endothelium-independent relaxation. GBSA significantly decreased the level of NO and the activity of SOD but hugely increased the content of MDA in vascular tissues. Pre-incubation of aortic rings with puerarin markedly attenuated the inhibition of endothelium-dependent relaxation induced by GBSA. This protective effect of puerarin (1 g · L-1) was partially inhibited by L-NAME but not by indomethacin. Puerarin obviously increased NO level and SOD activity but evidently decreased MDA content in rings. CONCLUSION: Puerarin can protect against vascular endothelial dysfunction caused by GBSA and its mechanisms may be related to enhancing NO synthesis and its anti-oxidation.

Psychological stress reduces the plasma NO level and NO-regulating protein expression in the vascular en-dothelial cells of rats / 医学研究生学报

[Abstract ] Objective The mechanism of psychological stressi-nduced damage to vascular endothelial cells (VEC) is not yet clear.This study was to investigate the impact of psychological stress on the NO level and NO-related regulatory protein expression in the plasma of rat models of psychological stress-induced VEC injury. Methods Twenty male SD rats were equally randomized into a con-trol group and a model group, the former raised together, with water regularly fed at 9:00 and 21:00 hours for 10 minutes a day, while the latter raised alone, with water regularly fed at the same hours for 10 minutes a day for the first 7 days and then with water or an empty bottle at the same hours for 10 minutes a day according to the random table.Ninety days later,all the rats were intraperitoneally injected with normal saline at 0.2 ml per 100 g body weight twice a day.Then the behaviors of the animals were observed by open field tests, the contents of cortisol (COR),adrenaline (Adr), and endothelin-1 (ET-1) in the plasma measured by ELISA, the NO level detected by the nitrate reductase method, and the expression of NO-related regulatory proteins in VECs determined by LC-ESI-MS. Results Com-pared with the control group, the model rats showed significant increases in the vertical score (7.00 ±0.70 vs 11.28 ±1.79), horizontal score (37.60 ±4.500 vs 56.25 ±1.71), and total score (44.50 ±5.50 vs 67.25 ±2.98) (P<0.01) as well as in the levels of COR ([65.28 ±2.21] vs [83.85 ±1.95] ng/mL ) and Adr ([3.85 ±0.35] vs [15.14 ±3.97] pg/mL) (P<0.01), but a remarkable de-with vacuoles in the VECs in the model group and structural integrity, ridge clarity, and tight pack in the VEC mitochondria in the con-trol. Conclusion Psychological stress induced by empty bottle stimulation can reduce the NO level and the expression of NO-related regulatory proteins in the plasma, which may cause both functional and structural damages to VECs.