To examine the role of nitric oxide in the beta-adrenergic vasodilation of epicardial coronary arteries in dogs, 12 dogs were instrumented for measurement of left anterior descending coronary artery diameter by transthoracic echocardiography before and after dobutamine (5 microg/kg/min IV) with and without intracoronary infusion of NG-monomethyl-L-arginine (L-NMMA) (1 mg/kg). In all 12 dogs, the diameter of left anterior descending coronary artery increased significantly from 2.35 +/- 0.25 mm to 2.59 +/- 0.24 mm (P<0.001) after dobutamine administration. In 6 of the 12 dogs, the percent change in left anterior descending coronary artery diameter induced by dobutamine decreased significantly from 12.5% +/- 8.6% to -1.5% +/- 5.4% (P<0.05) after the administration of intracoronary L-NMMA (1 mg/kg for 5 min) to block nitric oxide synthesis from L-arginine. The study demonstrated that nitric oxide formation contributes to the beta-adrenergic dilatory response of epicardial coronary arteries to dobutamine in dogs.
Adrenergic beta-Agonists ; pharmacology ; Animals ; Coronary Vessels ; physiology ; Dobutamine ; pharmacology ; Dogs ; Echocardiography ; Female ; Male ; Nitric Oxide ; physiology ; Receptors, Adrenergic, beta ; physiology ; Vasodilation ; physiology ; omega-N-Methylarginine ; pharmacology

PURPOSE: The purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells. MATERIALS AND METHODS: Human IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650Omega, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [3H]-thymidine, and [35S]-sulfate incorporation. To detect phenotypical expression, reverse transcription-polymerase chain reactions (RT-PCR) were performed for aggrecan, collagen type I, and type II mRNA expression. To assess action mechanism of EMF, IVD cells were exposed to EMF with NG-Monomethyl-L-arginine (NMMA) and acetylsalicylic acid (ASA). RESULTS: There was no cytotoxicity in IVD cells with the EMF group in MTT assay. Cellular proliferation was observed in the EMF group (p < 0.05). There was no difference in newly synthesized proteoglycan normalized by DNA synthesis between the EMF group and the control. Cultures with EMF showed no significant change in the expression of aggrecan, type I, and type II collagen mRNA compared to the control group. Cultures with NMMA (blocker of nitric oxide) or ASA (blocker of prostaglandin E2) exposed to EMF demonstrated decreased DNA synthesis compared to control cultures without NMMA or ASA (p < 0.05). CONCLUSION: EMF stimulated DNA synthesis in human IVD cells while no significant effect on proteoglycan synthesis and chondrogenic phenotype expressions. DNA synthesis was partially mediated by nitric oxide and prostaglandin E2. EMF can be utilized to stimulate proliferation of IVD cells, which may provide efficient cell amplification in cell therapy to degenerative disc disease.
Adult ; Aspirin/pharmacology ; Cell Proliferation/*radiation effects ; Collagen/metabolism ; Dinoprostone/metabolism ; *Electromagnetic Fields ; Enzyme Inhibitors/pharmacology ; Female ; Humans ; Intervertebral Disk/*pathology/radiation effects ; Male ; Middle Aged ; Nitric Oxide/metabolism ; Tetrazolium Salts/pharmacology ; Thiazoles/pharmacology ; omega-N-Methylarginine/pharmacology

OBJECTIVETo dynamically observe the effect of Safflower Injection (SI) on mesenteric microvascular motion in vivo in rabbits, and to explore the effect of nitric oxide (NO) in the process to further investigate the action mechanism of activating blood to remove stasis of SI.

METHODSTwenty healthy male albino rabbits were intraperitoneally injected with urethane for basic anesthesia and injected with alpha-chloralose via ear marginal venous to maintain anesthesia, spontaneously ventilated via tracheotomy tube, with the in-step record of breath and blood pressure. The vasomotion was induced by noradrenaline (NA) in vivo, then the changes of vasomotion after injecting SI and N(G)-monomethyl-L-arginine (L-NMMA, a NO synthase inhibitor) were measured respectively on a TV monitor using a TV camera mounted on the microscope, and the influence of L-NMMA on effect of SI was also observed.

RESULTSL-NMMA injection alone can inhibit the NA induced vasomotion in vasoconstriction state, while SI injection alone can inhibit it in vaso-dilation state. SI could abolish the effect of L-NMMA on vasomotion but L-NMMA did not influence the effect of SI on vasomotion. CONCLUSION SI can inhibit vasomotion in vaso-dilation status, but its mechanism is not mediated by endogenous NO.

Animals ; Carthamus tinctorius ; chemistry ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Injections ; Male ; Mesentery ; blood supply ; Microcirculation ; drug effects ; Rabbits ; Vasodilator Agents ; administration & dosage ; pharmacology ; omega-N-Methylarginine ; administration & dosage ; pharmacology

OBJECTIVETo detect the nitric oxide (NO) production and energy metabolism of the interleukin (IL)-1beta-treated residual hepatocytes from rats after partial hepatectomy.

METHODSForty rats were equally divided into partial hepatectomies (PH) group and control group. In the control group the rats were otherwise matched and underwent sham surgeries. The residual hepatocytes were separated by the collagenase perfusion method. The hepatocytes were cultured with cytokines such as IL-1beta. The production of NO in the two groups were measured with Griess reagent method, the production of inducible nitric oxide synthase (iNOS) protein detected with Western blot, the content of the nucleotide in the hepatocytes detected with high-performance liquid chromatography, and the content of the ketone body in the hepatocytes of the two groups determined with the enzymatic method. Afterwards the ketone body ratio (acetoacetate/beta-hydroxy butyrate, KBR) was calculated.

RESULTSThe production of NO in the PH group was twice as much as that in the Sham group. IL-1beta decreased the content of ATP and the KBR in the hepatocytes of both groups, and the decrease magni tude in the PH group was significantly larger than that in the Sham group. After the injection of L-arginine, the production of NO in the hepatocytes in the PH group increased, and the level of ATP and KBR decreased. N(G)-methyl-L-arginine (L-NMMA), the inhibitor of NO synthase, inhibited the production of NO and reversed the decrease of ATP and KBR.

CONCLUSIONAfter partial hepatectomy, increased NO production in the hepatocytes after the treatment of interleukin-1beta may disturb the function of mitochondria by inhibiting the synthesis of ATP.

Adenosine Triphosphate ; biosynthesis ; Animals ; Arginine ; pharmacology ; Cells, Cultured ; Hepatectomy ; Hepatocytes ; metabolism ; Interleukin-1beta ; pharmacology ; Ketone Bodies ; biosynthesis ; Nitric Oxide ; antagonists & inhibitors ; biosynthesis ; Nitric Oxide Synthase ; antagonists & inhibitors ; Rats ; omega-N-Methylarginine ; pharmacology

This study was designed to determine the inhibitory effect of astragaloside Ⅳ(AS-Ⅳ), a principal bioactive component extracted from the Chinese medicinal Astragali Radix, on the inflammatory response of vascular endothelial cells induced by angiotensin Ⅱ(Ang Ⅱ), the most major pathogenic factor for cardiovascular diseases, and to clarify the role of calcium(Ca~(2+))/phosphatidylinosi-tol-3-kinase(PI3K)/protein kinase B(Akt)/endothelial nitric oxide synthase(eNOS)/nitric oxide(NO) pathway in the process. To be specific, human umbilical vein endothelial cells(HUVECs) were cultured in the presence of AS-Ⅳ with or without the specific inhibitor of NO synthase(NG-monomethyl-L-arginine, L-NMMA), inhibitor of PI3K/Akt signaling pathway(LY294002), or Ca~(2+)-chelating agent(ethylene glycol tetraacetic acid, EGTA) prior to Ang Ⅱ stimulation. The inhibitory effect of AS-Ⅳ on Ang Ⅱ-induced inflammatory response and the involved mechanism was determined with enzyme-linked immunosorbent assay(ELISA), cell-based ELISA assay, Western blot, and monocyte adhesion assay which determined the fluorescently labeled human monocytic cell line(THP-1) adhered to Ang Ⅱ-stimulated endothelial cells. AS-Ⅳ increased the production of NO by HUVECs in a dose-and time-dependent manner(P<0.05) and raised the level of phosphorylated eNOS(P<0.05). The above AS-Ⅳ-induced changes were abolished by pretreatment with L-NMMA, LY294002, or EGTA. Compared with the control group, Ang Ⅱ obviously enhanced the production and release of cytokines(tumor necrosis factor-α, interleukin-6), chemokines(monocyte chemoattractant protein-1) and adhesion molecules(intercellular adhesion molecule-1, vascular cellular adhesion molecule-1), and the number of monocytes adhered to HUVECs(P<0.05), which were accompanied by the enhanced levels of phosphorylated inhibitor of nuclear factor-κBα protein and activities of nuclear factor-κB(NF-κB)(P<0.05). This study also demonstrated that Ang Ⅱ-induced inflammatory response was inhibited by pretreatment with AS-Ⅳ(P<0.05). In addition, the inhibitory effect of AS-Ⅳ was abrogated by pretreatment with L-NMMA, LY294002, or EGTA(P<0.05). This study provides a direct link between AS-Ⅳ and Ca~(2+)/PI3K/Akt/eNOS/NO pathway in AS-Ⅳ-mediated anti-inflammatory actions in endothelial cells exposed to Ang Ⅱ. The results indicate that AS-Ⅳ attenuates endothelial cell-mediated inflammatory response induced by Ang Ⅱ via the activation of Ca~(2+)/PI3K/Akt/eNOS/NO signaling pathway.
Humans ; Angiotensin II/pharmacology* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; omega-N-Methylarginine/pharmacology* ; Egtazic Acid/pharmacology* ; Human Umbilical Vein Endothelial Cells ; NF-kappa B/metabolism* ; Nitric Oxide/metabolism* ; Cells, Cultured

OBJECTIVETo investigate the effects of prostacyclin (PGI(2)) and nitric oxide (NO) in the development of hyperdynamic circulatory state on chronic portal hypertensive rats.

METHODSSixty-six male SD rats were divided into three groups, namely intrahepatic portal hypertension (IHPH) by injection of CCl(4), prehepatic portal hypertension (PHPH) by partial stenosis of the portal vein for 2 weeks and sham-operated controls (SO). Animals in each group were divided further into 3 subgroups and received N(omega)-nitro-L-arginine (L-NNA), indomethacin and saline (as control), respectively. Splanchnic and systemic hemodynamics was measured using radioactive microsphere techniques. The NO concentration in serum was determined by nitrates-nitrites which were measured using a colorimetric method, and concentration of PGI(2) was determined using specific radioimmunoassay for its stable hydrolytic product, 6-keto-PGF(1 alpha).

RESULTSThe concentrations of plasma 6-keto-PGF(1 alpha) and serum nitrates + nitrites in IHPH rats (1 123.85 +/- 153.64; 73.34 +/- 4.31) and in PHPH rats (891.88 +/- 83.11; 75.21 +/- 6.89) were significantly higher than those of SO rats (725.53 +/- 105.54;58.79 +/- 8.47). L-NNA and indomethacin could decrease the concentrations of plasma 6-keto-PGF(1 alpha) and serum nitrates + nitrites in IHPH and PHPH rats (P < 0.05). At the same time, CI, FPP and PVI were lowered while MAP, TPR and SVR were increased (P < 0.05). After deduction of NO action, there were no significant correlation between plasma PGI(2) level and hemodynamic parameters such as CI, TPR, PVI and SVR. However, after deduction of PGI(2) action, NO was still correlated highly with those hemodynamic parameters.

CONCLUSIONIt is NO rather then PGI(2) that is a mediator in the formation and development of hyperdynamic circulatory state in chronic portal hypertensive rats.

6-Ketoprostaglandin F1 alpha ; blood ; Animals ; Cyclooxygenase Inhibitors ; pharmacology ; Disease Models, Animal ; Enzyme Inhibitors ; pharmacology ; Epoprostenol ; blood ; physiology ; Hemodynamics ; drug effects ; Hypertension, Portal ; blood ; physiopathology ; Male ; Nitric Oxide ; blood ; physiology ; Nitric Oxide Synthase ; antagonists & inhibitors ; Nitroarginine ; blood ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; omega-N-Methylarginine ; pharmacology

OBJECTIVETo investigate the differential expression of isocitrate lyase in Penicillium marneffei phagocytized by nonstimulated and stimulated murine macrophages, and explore the role of glyoxylate pathway in pathogenesis of Penicilliosis marneffei.

METHODSPenicillium marneffei conidia and Raw264.7 cells were incubated in 16 cultures, which were divided to 4 groups for treatment with N-monomethyl-L-arginine (LNMMA, CI group), murine interferon-gamma (IFN-gamma) plus lipopolysaccharide (LPS) (T group), IFN-gamma plus LPS and LNMMA (TI group), or the same volume of culture medium (C group). The transcriptional levels of isocitrate lyase were detected using real-time RT-PCR, and its expression levels detected biochemically.

RESULTSThe transcriptional levels of isocitrate lyase in C, CI, T, TI groups were 1.00, 1.42, 33.09, and 74.88 (P<0.05), while the expression levels were 0.06, 0.07, 0.18, and 0.93, respectively (P<0.05). The content of nitric oxide in T group was significantly higher than that in the other groups (P<0.01), but the CFU of T group was the lowest (P<0.01).

CONCLUSIONReactive nitrogen intermediates induced by stimulated murine macrophages restrain the expression of isocitrate lyase of Penicillium marneffei and development of Penicillium marneffei, in which process the glyoxylate pathway may play an important role.

Animals ; Cell Line ; Fungal Proteins ; genetics ; Gene Expression Profiling ; Gene Expression Regulation, Enzymologic ; drug effects ; Gene Expression Regulation, Fungal ; drug effects ; Host-Pathogen Interactions ; Interferon-gamma ; pharmacology ; Isocitrate Lyase ; genetics ; Lipopolysaccharides ; pharmacology ; Macrophages ; drug effects ; immunology ; microbiology ; Mice ; Nitric Oxide ; immunology ; Penicillium ; genetics ; immunology ; physiology ; Phagocytosis ; immunology ; Reverse Transcriptase Polymerase Chain Reaction ; omega-N-Methylarginine ; pharmacology

BACKGROUND: The effects of antihypertensive agents on endothelial function have not been fully evaluated in human hypertension and data on the forearm circulation of humans are controversial. The aim of this study was (1) to evaluate the endothelial function in hypertensive patients (2) to investigate whether vitamin C administration has any benefit on the endothelial function and (3) to determine whether treatment with calcium antagonist improves endothelial dysfunction in hypertensive patients. METHODS: The endothelial function was estimated using venous occlusion plethysmography (VOP) in 8 hypertensive patients and 8 healthy volunteers. The patients in the hypertension group were treated with amlodipine, then examined again. The change of forearm blood flow (FBF) was measured with acetylcholine infusion through brachial artery and also with intra-arterial vitamin C. RESULTS: Forearm blood flow response to acetylcholine was significantly enhanced with intra-arterial infusion of vitamin C in hypertensive group before antihypertensive treatment. Co-infusion of L-NMMA, an inhibitor of nitric oxide synthase, blunted forearm blood flow response to acetylcholine. After treatment with amlodipine for 2 months in hypertensive group, endothelium-dependent vasorelaxation to acetylcholine was significantly improved compared to pretreatment, and vitamin C did not affect the improved endothelial function by amlodipine treatment. CONCLUSION: Vitamin C (acutely) and amlodipine (chronically) improved endothelial function in hypertensive patients. These results suggest that increased oxidative stress, at least in part, may be involved in the decreased endothelial function in hypertension.
Adult ; Aged ; Amlodipine/*therapeutic use ; Antihypertensive Agents/therapeutic use ; Ascorbic Acid/*therapeutic use ; Calcium Channel Blockers/therapeutic use ; Endothelium, Vascular/*drug effects/*physiopathology ; Enzyme Inhibitors/pharmacology ; Female ; Human ; Hypertension/*drug therapy/*physiopathology ; Male ; Middle Age ; Nitric-Oxide Synthase/antagonists & inhibitors ; Vasodilation/drug effects ; omega-N-Methylarginine/pharmacology

The aim of this study was to explore the mechanism of the nervous system lesions induced by formaldehyde (FA). Male Balb/c mice were exposed to gaseous formaldehyde for 7 days (8 h/d) with three different concentrations (0, 0.5 and 3.0 mg/m(3)). A group of animals injected with the nitric oxide synthase inhibitor L-NMMA (0.01 mL/g) was also set and exposed to 3.0 mg/m(3) FA. The concentrations of cAMP, cGMP, NO and the activity of NOS in cerebral cortex, hippocampus and brain stem were determined by corresponding assay kits. The results showed that, compared with the control (0 mg/m(3) FA) group, the cAMP contents in cerebral cortex and brain stem were significantly increased in 0.5 mg/m(3) FA group (P < 0.05), but decreased in 3.0 mg/m(3) FA group (P < 0.05); The concentration of cAMP in hippocampus was significantly decreased in 3.0 mg/m(3) FA group (P < 0.05). In comparison with the control group, L-NMMA group showed unchanged cAMP contents and NOS activities in different brain regions, but showed increased cGMP contents in hippocampus and NO contents in cerebral cortex (P < 0.05). In addition, compared with 3.0 mg/m(3) FA group, L-NMMA group showed increased contents of cAMP and reduced NOS activities in different brain regions, as well as significantly decreased cGMP contents in cerebral cortex and brain stem and NO content in brain stem. These results suggest that the toxicity of FA on mouse nervous system is related to NO/cGMP and cAMP signaling pathways.
Animals ; Brain Stem ; chemistry ; drug effects ; Cerebral Cortex ; chemistry ; drug effects ; Cyclic AMP ; chemistry ; Cyclic GMP ; chemistry ; Formaldehyde ; toxicity ; Hippocampus ; chemistry ; drug effects ; Male ; Mice ; Mice, Inbred BALB C ; Nitric Oxide ; chemistry ; Nitric Oxide Synthase ; antagonists & inhibitors ; omega-N-Methylarginine ; pharmacology