AIM AND METHODSTo determine the relationship between the nuclear envelope nucleoside triphosphatase (EC 3. 6. 1. 15, NTPase) activity and the phenotypic modulation of vascular smooth muscle cell (VSMC), the NTPase activity was detected during restenosis after de-endothelialization in vascular wall. The activities of three enzymes involved in carbohydrate and nucleic acid metabolism were also investigated by spectrophotometry.

RESULTSThe activity of NTPase increased continuously and associated with the process of intimal thickening. Western blotting showed that expression of SMalpha-actin, as the marker of contractile phenotype of VSMC, decreased continuously. Osteopontin (OPN), the marker of synthetic phenotype of VSMC, was up-regulated during the process. These suggested that intimal injury induced phenotypic modulation of VSMC. The activities of 5'-nucleotidase, adenosine deaminase and succinate dehydrogenase increased and reached their peaks on 7 days after de-endothelialization. The changes of three enzymes were associated with proliferation in VSMC.

CONCLUSIONThe efflux of mRNA and the changes of enzyme activity involved in carbohydrate or nucleic acid metabolism may be the biochemical basis in the development and progression of restenosis.

Animals ; Constriction, Pathologic ; Endothelium, Vascular ; pathology ; Female ; Hyperplasia ; enzymology ; pathology ; Male ; Muscle, Smooth, Vascular ; pathology ; Nucleoside-Triphosphatase ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tunica Intima ; enzymology ; pathology

OBJECTIVE: To detect the expression and activity of eNOS during the arteriogenesis of hind-limbs of pigs. METHODS: The right femoral artery was ligated, and the left femoral artery shamly operated under routine surgical procedures. Animals were sacrificed after two weeks. The expression and activity of eNOS in collateral vessels were studied by confocal immunofluorescence with antibodies against eNOS and phosphorylated eNOS (P-eNOS) respectively. RESULTS: In normal small arteries, the expression of eNOS was very low, and the staining was very weak. In growing collateral vessels, the expression of eNOS was significantly up-regulated, showing very strong positive staining. The expression of P-eNOS was also high. Dural immunostaining showed that eNOS and P-eNOS were colocalized in the endothelial cells. CONCLUSION eNOS is up-regulated and activated during arteriogenesis, suggesting that eNOS can exert the possible role in mediating the proliferation of endothelial cells and the inflammation, and contribute to the collateral vessel growth.
Animals ; Collateral Circulation ; physiology ; Endothelial Cells ; enzymology ; Endothelium, Vascular ; enzymology ; Femoral Artery ; pathology ; surgery ; Hindlimb ; blood supply ; Ligation ; Neovascularization, Physiologic ; Nitric Oxide Synthase Type III ; biosynthesis ; genetics ; Swine

OBJECTIVETo explore the effect of benzo(a)pyrene (BaP) on the expression and the activities of cytochrome P450 1A1 (CYP1A1) of porcine aortic endothelial cells.

METHODSPorcine aortic endothelial cells were cultured in vitro, and treated with different concentrations of BaP (0, 0.5, 1.0, 5.0, 10.0 micro mol/L) for 24 hours, CYP1A1 expression was determined by Western blot and immunohistochemistry. At the same time, the ethoxyresorufin-o-deethylase (EROD) activities were measured by spectrofluorometer.

RESULTSBy Western blot, the expression of CYP1A1 of control cells was not found, but the expression of CYP1A1 of cells treated with BaP was found; By immunohistochemistry, only part of endothelial cells treated with BaP had positive expression of CYP1A1. The peak activities of EROD induced by BaP was at the concentration of 0.5 - 1.0 micro mol/L.

CONCLUSIONBaP could induce part of endothelial cells to synthesize CYP1A1. BaP of 0.5 - 1.0 micro mol/L could induce peak activities of EROD.

Animals ; Benzo(a)pyrene ; toxicity ; Blotting, Western ; Cells, Cultured ; Cytochrome P-450 CYP1A1 ; analysis ; Dose-Response Relationship, Drug ; Endothelium, Vascular ; cytology ; drug effects ; enzymology ; Immunohistochemistry ; Swine

15-hydroxyeicosatetraenoic acid (15-HETE) plays an important role in hypoxia-induced pulmonary vasoconstriction. Release of nitric oxide (NO) is apparently decreased and activity of endothelial nitric oxide synthase (eNOS) is impaired in chronic hypoxia. However, little is known whether 15-HETE contributes to eNOS/NO pathway in the constriction induced by 15-HETE. We examined the response of rat pulmonary artery (PA) rings to 15-HETE, the production of NO, total eNOS expression and the phosphorylation of eNOS in bovine pulmonary artery endothelial cells (BPAECs) stimulated by 15-HETE. Rat PA rings were divided into three groups: endothelium intact group, endothelium denuded group, and nitro-L-arginine methyl ester (L-NAME, 0.1 mmol/L, an inhibitor of eNOS) group. Constrictions to 15-HETE were significantly enhanced in endothelium denuded group and L-NAME group (both P< 0.05 vs endothelium intact group, n= 9); BPAECs were incubated in different conditions to test nitrite production by Greiss method. Nitrite production was significantly reduced by 1 mumol/L 15-HETE (P<0.05), and increased by the lipoxygenase inhibitors, 10 mumol/L cinnamyl 3,4- dihydroxy-[alpha] -cyanocinnamate (CDC, P< 0.05) and 0.1 mmol/L nordihydroguiairetic acid (NDGA, P< 0.01 ); Western blot analysis of extracts from BPAECs incubated with 15-HETE in different time was carried out to test total eNOS expression, and the expression was changed unobviously. Immunoprecipitation (IP) and Western blot analysis of cell extracts from BPAECs treated with 2 mumol/L 15-HETE in different length of time were accomplished, using phospo-eNOS-threonine 495 (Thr495, an inhibitory site) antibody for IP, and eNOS or 15-lipoxygenase (15-LO) antibodies for Western blot. 15-HETE depressed eNOS activity by increasing the levels of phospho-eNOS-Thr 495. The data suggest that eNOS/NO pathway is involved in PA constrictions induced by 15-HETE and that 15-HETE depresses eNOS activity by phosphorylation in Thr495 site. The protein interaction between phospho-eNOS (Thr495) and 15-LO is discovered for the first time.
Animals ; Cattle ; Down-Regulation ; drug effects ; Endothelium, Vascular ; cytology ; drug effects ; enzymology ; Hydroxyeicosatetraenoic Acids ; pharmacology ; In Vitro Techniques ; Male ; Nitric Oxide Synthase Type III ; metabolism ; Pulmonary Artery ; cytology ; enzymology ; physiology ; Rats ; Rats, Wistar

The purpose of this study was to investigate the change of aortic semicarbazide-sensitive amine oxidase (SSAO) activity in diabetic rats and examine the effect of 2-bromoethylamine (2-BEA) on SSAO activity and vascular endothelium in diabetic rats. SSAO was prepared from rat aorta. For assessment of the inhibitory effect, the enzymes were preincubated in the presence of different concentrations of 2-BEA before the addition of benzylamine in vitro. Type 1 diabetic rat model was induced by a single intraperitoneal injection of streptozotocin (STZ). Sprague Dawley (SD) rats were randomly divided into normal control group (NC), diabetic model group (DM), 2-BEA 5 mg/kg group, 2-BEA 20 mg/kg group (n = 10 in each group). 2-BEA was administered daily via intraperitoneal injection for 8 weeks. At the end of 8 weeks, blood sample was collected from the abdominal aorta. Plasma nitric oxide (NO) was determined by nitrate reductase method. Plasma endothelin-1 (ET-1) was determined by radioimmunoassay. Aorta SSAO was determined by high performance liquid chromatography. The aorta was prepared to observe morphological changes and ultramicroscopic structures. The results were as follows: Compared with NC group, aortic SSAO activity and the plasma ET-1 were significantly increased (P < 0.01), and plasma NO was significantly decreased (P < 0.01) in DM group. 2-BEA decreased plasma ET-1 and elevated plasma NO by inhibiting aortic SSAO activity in diabetic rats (P < 0.01), and 2-BEA 20 mg/kg group was more significant than 2-BEA 5 mg/kg group (P < 0.05). Endothelial injury of 2-BEA group rats was less serious than DM group. These results suggest that 2-BEA protect aortic endothelium by inhibiting aortic SSAO activity.
Amine Oxidase (Copper-Containing) ; metabolism ; Animals ; Aorta, Abdominal ; enzymology ; Diabetes Mellitus, Experimental ; enzymology ; Endothelin-1 ; blood ; Endothelium, Vascular ; drug effects ; Ethylamines ; pharmacology ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDThe most intimidatory pathological changes in patients with DM are cardiovascular illnesses, which are the major causes of death in diabetic patients and are far more prevalent than in nondiabetics because of accelerated atherosclerosis. In this study, we tried to clarify the changes in macrovascular endothelial ultrastructure and in the gene expression of endothelial nitric oxide synthase (eNOS)mRNA in diabetic rats.

METHODSThe study was conducted on 52 of 10-week old Sprague Dawley (SD) rats with body weight of (320 +/- 42) g. SD rats were divided into: experimental group treated with a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg), (male, n = 20, diabetes mellitus (DMM)); female, n = 12, diabetes mellitus female (DMF)) and control group (male, n = 10, diabetes mellitus male control (DMMC); female, n = 10, diabetes mellitus female control (DMFC)). Four weeks after treatment, half of the rats were sacrificed; the remainders were sacrificed ten weeks after treatment. One part of the abdominal aortic sample was stored under glutaraldehyde (volume fraction psiB = 2.5%). After the process of chemical fixation, chemical dehydration, drying and conductivity enhancement, all samples were observed and photographed using scanning electron microscopy (Leica-Stereoscan 260, England). The other part of the abdominal aortic sample was treated with liquid nitrogen and the expression of eNOSmRNA was assessed by semi-quantitative RT-PCR.

RESULTSThe aortic lumen of both experimental groups adsorbed much more debris than that of either control group. The endothelial surfaces of diabetic rats were coarse, wrinkled and protuberant like fingers or villi. The vascular endothelial lesions of diabetic male rats were very distinct after 4 weeks, and as obvious as those at 10 weeks. The vascular endothelial lesions of diabetic female rats were not severe at 4 weeks and only became marked after 10 weeks. In both males and females, the abdominal aortic eNOSmRNA content of 4 weeks and 10 weeks diabetic rats was very significantly lower (P < 0.01) than that of controls.

CONCLUSIONSAortic endothelial ultrastructure in DM rats is injured compared with controls. Abnormal changes of aortic endothelia in male DM rats are more obvious than those in females. Expression of abdominal aortic eNOSmRNA content of DM rats is significantly lower than that of controls.

Animals ; Aorta, Abdominal ; enzymology ; Blood Glucose ; analysis ; Diabetes Mellitus, Experimental ; enzymology ; pathology ; Endothelium, Vascular ; ultrastructure ; Female ; Male ; Nitric Oxide Synthase ; genetics ; Nitric Oxide Synthase Type III ; RNA, Messenger ; blood ; Rats ; Rats, Sprague-Dawley ; Sex Factors ; Streptozocin

OBJECTIVETo investigate the relationship between angiotensin converting enzyme (ACE) gene and endothelial dysfunction.

METHODSOne hundred and ten type 2 diabetic patients without angiopathy were selected randomly, and PCR technique was used to determine their ACE genotypes. High resolution ultrasonography was performed to measure the changes in brachial artery diameter at rest, after reactive hyperemia (with increased flow producing an endothelium-dependent dilation) and after sublingual glyceryltrinitrate (GNT, an endothelium-independent dilator). Meanwhile, 50 healthy individuals were selected randomly as controls.

RESULTSIn type 2 diabetes mellitus and control groups, the percentages for flow-mediated arterial dilation in patients with DD genotypes were 3.38% and 3.67% respectively, which were significantly lower than those in patients with II genotypes (4.12% and 4.68% respectively, P<0.05). The baseline blood vessel size, baseline blood flow and GNT induced dilation in both groups showed no significant differences among ACE genotypes (P>0.05). By multiple stepwise regression analysis, reduced flow-mediated arterial dilation was associated with age, baseline vessel size, low density lipoprotein cholesterol(LDL-C), Lp(a), D allele, fasting blood glucose (FBG), postparandial blood glucose (PPBG), HbA1c, duration of diabetes in type 2 diabetic patients (P<0.0005).

CONCLUSIONACE DD genotype is related to endothelium-dependent arterial dilation in the early stage of type 2 diabetes mellitus and in healthy individuals.

Adult ; Aged ; Brachial Artery ; physiopathology ; Diabetes Mellitus, Type 2 ; enzymology ; genetics ; physiopathology ; Diabetic Angiopathies ; genetics ; physiopathology ; Endothelium, Vascular ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Peptidyl-Dipeptidase A ; genetics ; Polymerase Chain Reaction

AIMTo observe the effects of inulicin on the neointimal hyperplasia and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) after balloon injury in rat aorta.

METHODSThe intimal hyperplasia model was replicated by balloon injury. The histological changes in vascular wall were observed by HE staining. MMP-2 activation was tested by gelatin zymogram analysis; MMP-2 and TIMP-2 expression was detected by Western blot and immunohistochemistry analysis.

RESULTSNeointimal hyperplasia induced by balloon injury was significantly inhibited by inulicin. The proteolytic activity and the expression of MMP-2 and ratio of MMP-2 and TIMP-2 were also returned to control level by inulicin after balloon injury.

CONCLUSIONInulicin inhibits hyperplasia of neointima by modulating the balance of MMP-2 and TIMP-2.

Animals ; Endothelium, Vascular ; drug effects ; enzymology ; metabolism ; Hyperplasia ; prevention & control ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Neointima ; prevention & control ; Rats ; Rats, Sprague-Dawley ; Sesquiterpenes ; pharmacology ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism

BACKGROUNDIncreasing evidences indicate that an activated renin-angiotensin system (RAS) causes an imbalance between the vasoconstrictive and vasodilator mechanisms involving the pulmonary circulation leading to the development of pulmonary arterial hypertension (PAH). Angiotensin-converting enzyme 2 (ACE2), a primary component of the vasoprotective axis in RAS, is recently identified that it has regulatory actions in lung pathophysiology, but the mechanism in these processes is uncertain yet.

METHODSSevere PAH was induced by monocrotaline injection one week following pneumonectomy in rats. The activation of ACE2 by continuous injection of resorcinolnaphthalein was studied by real time-polymerase chain reaction (RT-PCR), Western blotting and fluorogenic peptide assay. Endothelial functions were evaluated by the response to acetylcholine and cytokines were measured by RT-PCR seven days after monocrotaline injection. The PAH-related hemodynamics and pathological changes were examined at day 21 when severe PAH was completely established.

RESULTSResorcinolnaphthalein caused significant activation of ACE2 in both normal and diseased rats in 7 days after treatment. The pulmonary arterial pressure (PAP) started to increase at least 7 days after monocrotaline injection, and the rats developed severe PAH in 21 days with high PAP, right ventricular hypertrophy and neointimal formation. Treatment with resorcinolnaphthalein prevented these features. Resorcinolnaphthalein caused an improved endothelia-dependent vasorelaxation and decrease in proinflammatory cytokines (tumor necrosis factor (TNF)-α, monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-6) and increase in anti-inflammatory cytokine IL-10 in the early stage of the pathogenesis.

CONCLUSIONSThese results demonstrated that activation of ACE2 by continuous injection of resorcinolnaphthalein prevented the development of PAH through improving early endothelial dysfunction and mediating the level of proinflammatory and anti-inflammatory cytokines.

Animals ; Cytokines ; biosynthesis ; Endothelium, Vascular ; physiology ; Enzyme Activation ; drug effects ; Familial Primary Pulmonary Hypertension ; Hypertension, Pulmonary ; enzymology ; prevention & control ; Inflammation ; prevention & control ; Male ; Peptidyl-Dipeptidase A ; physiology ; Rats ; Rats, Sprague-Dawley ; Resorcinols ; pharmacology

To elucidate the role of nitric oxide synthase (NOS) in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), we analyzed the expression of constitutive neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) in the spinal cords of rats with EAE. We further examined the structural interaction between apoptotic cells and spinal cord cells including neurons and astrocytes, which are potent cell types of nitric oxide (NO) production in the brain. Western blot analysis showed that three forms of NOS significantly increased in the spinal cords of rats at the peak stage of EAE, while small amounts of these enzymes were identified in the spinal cords of rats without EAE. Immunohistochemical study showed that the expression of either nNOS or eNOS increased in the brain cells including neurons and astrocytes during the peak and recovery stages of EAE, while the expression of iNOS was found mainly in the inflammatory macrophages in the perivascular EAE lesions. Double labeling showed that apoptotic cells had intimate contacts with either neurons or astrocytes, which are major cell types to express nNOS and eNOS constitutively. Our results suggest that the three NOS may play an important role in the recovery of EAE.
Animals ; Apoptosis ; Encephalomyelitis, Autoimmune, Experimental/*enzymology ; Endothelium, Vascular/enzymology ; Immunohistochemistry ; In Situ Nick-End Labeling ; Male ; Nitric Oxide Synthase/*metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Rats ; Rats, Inbred Lew ; Spinal Cord/*enzymology/pathology