A comparative study on the circadian rhythm of the electrical signals of Broussonetia papyrifera and Morus alba.

The circadian clock regulates a wide range of physiological processes in plants. Here we showed the circadian variations of the electrical signals in Broussonetia papyrifera L. and Morus alba L. in a natural state, which were analyzed using the day-night cycle method. The circadian characteristics of different plant electrical signals were compared by constructing a coupling model for the circadian rhythm of plant electrical signals. The electrical signal sensor had two electrode plates, which were fixed on the two ends of the splint, leaves could then be clamped and measured. The clamping force between the two electrode plates was uniform, which enabled continuous and nondestructive measurements. The results showed that an electric cyclic behavior was observed (circadian cycle) with the circadian variation in the plants within 24 h. Both the resistance (R) and the impedance (Z) increased firstly in the early morning and then decreased subsequently, while the capacitance (C) showed an opposite variation. Under different weather conditions, plant electrical signals showed periodic changes when the temperature and light intensity in the environment slightly changed within the physiological tolerance of plant. This indicated that the circadian clock of plant electrical signals could be maintained endogenously. The variation curves of plant electrical signals as time increased were fitted using the sine equation. The characteristic parameters of circadian rhythm of plant electrical signals were obtained. We found that although all plant electrical signals exhibited electric cyclic behavior, but the characteristics of circadian rhythms of electrical signals were different. This study provided a scientific basic for precisely monitoring plant electrical signals, and a reference for revealing circadian rhythms of plant electrical signals and their occurrence rules.

Swimming exercise inhibits myocardial ER stress in the hearts of aged mice by enhancing cGMP­PKG signaling.

The purpose of the present study was to explore aging­associated cardiac dysfunction and the possible mechanism by which swimming exercise modulates cardiac dysfunction in aged mice. Aged mice were divided into two groups: i) Aged mice; and ii) aged mice subjected to swimming exercises. Another cohort of 4­month­old male mice served as the control group. Cardiac structure and function in mice were analyzed using hematoxylin and eosin staining, and echocardiography. The levels of oxidative stress were determined by measuring the levels of superoxide dismutase, malondialdehyde and reactive oxygen species (ROS). Levels of the endoplasmic reticulum (ER) stress­related protein PKR­like ER kinase, glucose­regulated protein 78 and C/EBP homologous protein were determined to evaluate the level of ER stress. The aged group exhibited an abnormal cardiac structure and decreased cardiac function, both of which were ameliorated by swimming exercise. The hearts of the aged mice exhibited pronounced oxidative and ER stress, which were ameliorated by exercise, and was accompanied by the reactivation of myocardial cGMP and suppression of cGMP­specific phosphodiesterase type 5 (PDE5). The inhibition of PDE5 attenuated age­induced cardiac dysfunction, blocked ROS production and suppressed ER stress. An ER stress inducer abolished the beneficial effects of the swimming exercise on cardiac function and increased ROS production. The present study suggested that exercise restored cardiac function in mice with age­induced cardiac dysfunction by inhibiting oxidative stress and ER stress, and increasing cGMP­protein kinase G signaling.

[Comparative study on laparoscopic vaginoplasty using pedicled ileal and sigmoid colon segment transfer].

OBJECTIVE: To study the clinical effect of laparoscopic vaginoplasty using pedicled ileal and sigmoid colon segment. METHODS: From January 2004 to December 2009, 105 cases undergoing laparoscope-assisted vaginoplasty using a vascularized pedicled intestinal flap were studied retrospectively. Operation time, blood loss in operating, bowel movement after operation, postoperation hospital duration, side effect, and artificial vagina were compared between two surgical management. RESULTS: The vaginoplasty were preformed successfully in all 105 cases. There were 48 patients treated by aparoscope-assisted ileal vaginoplasty and 57 patients treated by laparoscope-assisted sigmoid colon vaginoplasty. The values of the operation time [(141 ± 22) minutes versus (159 ± 18) minutes, P = 0.000], blood loss in operating [(42 ± 6) ml versus (83 ± 14) ml, P = 0.000], bowel movement after operation (36 ± 9) hours versus (68 ± 8) hours(P = 0.000), and postoperation hospital duration [(9.8 ± 2.0) days versus (11.1 ± 1.3) days, P = 0.004] in the sigmoid colon vaginoplasty group were longer or higher than those in ileal vaginoplasty group (P < 0.05).No intraoprative complication occurred. There were four postoperative complications: 2 cases with intestinal obstruction in sigmoid colon vaginoplasty group, 1 case with urethral orifice stenosis and 1 case with vaginal-rectal fistula in ileal vaginoplasty group. At follow-up of 6-62 months, all artificial vaginas had a capacity of over two fingers in wideness and 12-15 cm in length. Vaginal discharges resembled a milky white water or mucus without odour. Fifty-five patients with sexual intercourse reported satisfactory results.Six patients complained vaginal stenosis:5 patients in ileal vaginoplasty group and 1 patient in sigmoid colon vaginoplasty group. CONCLUSIONS: Laparoscope-assisted vaginoplasty using pedicled ileum or sigmoid colon segment are both the effective ways in forming vagina. The latter management takes more time and blood loss while operating, yet the incidence of vaginal opening contracture appeared to be decreasing trend.

Assessment of left ventricular myocardial systolic acceleration in diabetic rats using velocity vector imaging.

OBJECTIVES: The purpose of this study was to investigate how the myocardial acceleration during isovolumic contraction changed in rats with diabetic cardiomyopathy and a normal left ventricular ejection fraction (LVEF) by using velocity vector imaging. METHODS: Velocity vector imaging was performed in 12 control rats and 15 rats with streptozotocin-induced diabetic cardiomyopathy 12 weeks after streptozotocin injection. The segmental radial displacement, velocity, acceleration, and percent wall thickening were measured at the mid-left ventricular (LV) level. RESULTS: Compared to control rats, rats with cardiomyopathy had a significant decrease in the peak radial acceleration during isovolumic contraction in most segments of the LV wall (including the anterior, anterolateral, inferolateral, and inferior segments; P < .05) but a similar LVEF, fractional shortening, and segmental displacement. Rats with cardiomyopathy also had a significant increase in LV end-diastolic and end-systolic diameters when corrected for body mass (P < .001; P = .003, respectively) and a significant decrease in the radial peak systolic velocities of the inferolateral and inferior wall segments (P < .05). In addition, rats with cardiomyopathy had a significant decrease in the peak radial diastolic acceleration in most segments of the LV wall (except for the anterolateral one; P< .05) but similar peak radial diastolic velocities in all LV wall segments compared to controls. Pathologic examination in rats with cardiomyopathy revealed ultrastructural impairment of the capillary and cardiocyte without any atherosclerotic lesion in the coronary artery compared to control rats. CONCLUSIONS: Myocardial acceleration during isovolumic contraction decreases in rats with diabetic cardiomyopathy and a preserved LVEF, suggesting the presence of regional LV systolic dysfunction.

[Advance in study of vascular endothelial cell and smooth muscle cell co-culture system].

The interactions between endothelial cells (EC) and smooth muscle cells (SMC) contribute to vascular physiological functions and also cause the occurrence and development of different kinds of diseases. Currently, EC-SMC co-culture model is the best way to study the interactions between the two kinds of cells. This article summarizes existing EC-SMC co-culture models and their effects on the structure and functions of the two kinds of cells. Microscopically speaking, it provides a basis for in-depth studies on their interactions as well as a reference for the establishment of in vitro EC-SMC co-culture system that is closer to organic physiology or pathology state.

The left ventricular intracavitary vortex during the isovolumic contraction period as detected by vector flow mapping.

AIMS: The purpose of this study was to characterize left ventricular (LV) intracavitary flow during the isovolumic contraction (IVC) period in humans using vector flow mapping. METHODS: Color flow Doppler imaging was performed from the apical long-axis view in 61 patients with heart failure and 58 healthy volunteers. Doppler flow data obtained during IVC were analyzed offline with vector flow mapping. RESULTS: A large vortex was formed from the LV inflow toward the outflow during IVC. In normal subjects, the area of the vortex was sustained, but the flow volume decreased significantly during IVC (P < 0.001). A significant apex-to-base flow velocity gradient was shown along the outflow axis on aortic valve opening. However, both the area and flow volume of the vortex decreased more severely during IVC in the patients (P < 0.001). The apex-to-base flow velocity gradient along the outflow axis disappeared and a reversed velocity gradient was observed at the basal-mid level on aortic valve opening. In multivariate models, a decreased LV ejection fraction was the only independent predictor of the percentage decrease in area of the vortex during the IVC (P < 0.001), and a larger QRS width (P = 0.028) and LV end-systolic long diameter (P = 0.002) were independent predictors of the percentage decrease in flow volume of the vortex. CONCLUSIONS: The vortex across the LV inflow-outflow region during IVC facilitates the ejection of blood during early systole, and an unsustained vortex may be associated with impaired cardiac function.

Infrasound exposure induces apoptosis of rat cardiac myocytes by regulating the expression of apoptosis-related proteins.

It has been reported that exposure to infrasound causes cardiac dysfunction. Allowing for the key role of apoptosis in the pathogenesis of cardiovascular diseases, the objective of this study was to investigate the apoptotic effects of infrasound. Cardiac myocytes cultured from neonatal rats were exposed to infrasound of 5 Hz at 130 dB. The apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. Also, the expression levels of a series of apoptosis-related proteins were detected. As a result, infrasound induced apoptosis of cultured rat cardiac myocytes in a time-dependant manner. The expression of proapoptotic proteins such as Bax, caspase-3, caspase-8, caspase-9, and FAS was significantly up-regulated, with concomitant down-regulated expression of antiapoptotic proteins such as Bcl-x, and the inhibitory apoptosis proteins family proteins including XIAP, cIAP-1, and cIAP-2. The expression of poly (ADP-ribose) polymerase and ß-catenin, which are the substrate proteins of caspase-3, was significantly decreased. In conclusion, infrasound is an apoptotic inducer of cardiac myocytes.

AC-NP: a novel chimeric peptide with natriuretic and vasorelaxing actions.

The aim of this study was to evaluate the cardiovascular and renal activities of a newly designed natriuretic peptide (NP). Here, we engineered a novel 28-amino acid chimeric peptide, termed AC-NP that combined the 17-amino acid ring of C type natriuretic peptide (CNP) with the 6-amino acid N-terminus and 5-amino acid C-terminus of atrial natriuretic peptide (ANP). Both in vitro and in vivo experiments were performed to determine the actions of AC-NP. In normal rats, AC-NP proved to be more potentially diuretic, natriuretic and hypotensive compared with other NPs, such as ANP, CNP and vasonatrin peptide (VNP), which is another man-made NP. In relaxation of isolated abdominal aorta from rat, AC-NP was equally effective to ANP, CNP and VNP. Elevated levels of 3',5'-guanosine monophosphate (cGMP) in plasma and urine cGMP excretion indicated the participation of cGMP in the functions of AC-NP. Taken together, innovative designed AD-NP might be a new candidate therapeutic peptide against cardiorenal disorders.

Effects of genistein, apigenin, quercetin, rutin and astilbin on serum uric acid levels and xanthine oxidase activities in normal and hyperuricemic mice.

Flavonoids are widely found in plants and many of them possess biological and pharmacological activities. In the present study, we assessed the effects of the flavonoids Genistein, Apigenin, Quercetin, Rutin and Astilbin on xanthine oxidase (XO) activities in vitro, and in serum and the liver. The effects of the flavonoids on serum uric acid levels were also measured in vivo. In vitro studies indicated that the flavonoids tested did not significantly affect XO activity. However, significant increases and decreases in XO activities were observed in vivo. Moreover, serum XO activity was correlated with serum uric acid levels, while no correlation was observed for liver XO activity. The present study showed that serum uric acid levels in mice treated with the flavonoids tested here are higher than control levels. Therefore, the flavonoids tested here are not candidates for replacing Allopurinol as a treatment to reduce serum uric acid levels.

Protecting effects of vasonatrin peptide against carbon tetrachloride-induced liver fibrosis.

In order to investigate the effects of vasonatrin peptide (VNP), a novel man-made natriuretic peptide, on liver fibrosis, mice received carbon tetrachloride (CCl(4)) injection for 12weeks and with or without VNP treatment during the last 6weeks. Hematoxylin-eosin (HE) staining and Sirius red staining were performed to evaluate the status of liver fibrosis. After treatment of VNP, DNA and collagen synthesis of cultured HSC-T6 hepatic stellate cells were assessed by [(3)H]-thymidine and [(3)H]-proline incorporation, respectively. Additionally, involved signaling pathway was identified by radioimmunoassay to detect the levels of intracellular cGMP and by mimicking experiments using 8-br-cGMP (a membrane-permeable cGMP analog). Also, blocking experiments were performed using HS-142-1, an antagonist of guanylyl cyclase-coupled natriuretic peptide receptor (NPR), or KT-5823, the cGMP-dependent protein kinase (PKG) inhibitor. As a result, VNP markedly alleviated CCl(4)-induced liver fibrosis in mice. In vitro, HSC-T6 cells demonstrated a dose-dependent reduction of DNA and collagen synthesis in the presence VNP. In addition, VNP significantly increased the intracellular levels of cGMP. These effects of VNP were mimicked by 8-br-cGMP, although inhibited by HS-142-1 or KT-5823. Taken together, VNP ameliorates liver fibrosis by inhibiting collagen production from hepatic stellate cells via guanylyl cyclase-coupled NPR/cGMP/PKG pathway, indicating that VNP might be a new effective reagent in the treatment of liver fibrosis.

[Extracts of danshen and chuanxinlian on human monocytic line THP-1 induced by TNF-alpha].

OBJECTIVE: To investigate whether extracts of Danshen and Chuanxinlian (SL) could promote the function recovery in pre-monocytic cell line THP-1 induced by TNF-alpha. METHOD: SL extracts (0.125-2 g x L(-1)) were used to incubate THP-1 for 24 h before stimulation with TNF-alpha (20 microg x L(-1)), the adhesion, migration, lipid uptake and secretion of THP-1 were observed. RESULT: SL (0.5-2 g x L(-1)) had obvious effect on decreasing the THP-1 adhesion. The number of passed membrane was much fewer than that of control cells in SL (0.125-2 g x L(-1)). SL (0.125-2 g x L(-1)) reduced the total cholesterol content significantly. The levels of IL-6 in SL (2 g x L(-1)) were significantly decreased,and IL-10 was increased than that before the treatment. CONCLUSION: SL extracts could promote the function recovery such as adhesion, migration, lipid uptake and secretion of THP-1 induced by TNF-alpha, which probably is one of the mechanisms of inhibit the inflammatory reaction in initiation and development of AS.

Protective effects of vasonatrin peptide against hypobaric hypoxia-induced pulmonary hypertension in rats.

1. The aim of the present study was to investigate the in vivo effects of vasonatrin peptide (VNP) on hypoxia-induced pulmonary hypertension (HPH). 2. The HPH model was developed by subjecting rats to hypobaric hypoxia. The HPH rats were then treated with either VNP (50 microg/kg per day, i.p.) or saline (0.5 mL, i.p.) every day for 7 days. Haemodynamic indices, right ventricular hypertrophy (RVH) and remodelling of the pulmonary arteries were evaluated. In addition, plasma levels of atrial natriuretic peptide (ANP), endothelin (ET)-1 and angiotensin II (AngII) were determined, as was natriuretic peptide receptor-C (NPR-C) mRNA expression in the right ventricle. 3. Hypobaric hypoxia induced severe HPH compared with the normoxic control group. Treatment of HPH rats with VNP for 1 week significantly reduced mean pulmonary arterial pressure, pulmonary vascular resistance, RVH and muscularization of the pulmonary arteries, although pulmonary blood flow was increased in this group. In addition, significantly lower levels of plasma ET-1 and AngII and cardiac NPR-C mRNA expression were observed in VNP-treated compared with saline-treated HPH rats, whereas higher plasma concentrations of ANP were found in the former group. Acute intravenous administration of 50 microg/kg VNP significantly ameliorated pulmonary haemodynamics in HPH rats. 4. Taken together, the date indicate that VNP has certain preventative and therapeutic effects against HPH.

Role of mast cell activation in inducing microglial cells to release neurotrophin.

The brain-derived neurotrophic factor (BDNF) plays a critical role in pain hypersensitivity. BDNF is the ligand of P2X4 receptors (P2X4R) in the microglia. The causative factors involving the P2X4R over expression in the microglia remains unclear. Mast cell activation has a close relation with pain hypersensitivity. However, the underlying mechanism between mast cell activation and pain hypersensitivity is unknown. The present study aimed to elucidate the mechanism by which mast cell activation promoted the expression of P2X4R in the microglia. The results of present study showed that mast cell activation markedly promoted the expression of P2X4R and BDNF in microglial cells, which significantly enhanced the release of BDNF from microglial cells upon exposure to adenosine triphosphate. Mast cell-derived tryptase activated PAR2 that resulted in promoting the expression of P2X4R in microglial cells. Pretreatment with antibodies against tryptase or PAR2, or using tryptase-deficient HMC-1 cells or PAR2-deficient microglial cells abolished the increase in P2X4R expression and BDNF release. Increase in mitogen activated protein kinase phosphorylation was observed in the processes of mast cell-induced BDNF release and P2X4R expression. We conclude that mast cell activation has the capacity to promote the expression of P2X4R and BDNF in microglial cells.

[Expression of ICOSL on human coronary artery endothelial cells and its being interferentialed by ox-LDL].

AIM: To study the expression of inducible co-stimulator ligand(ICOSL) on human coronary artery endothelial cells(HCAEC) and its being interferentialed by oxidized low density lipoprotein(ox-LDL). METHODS: ICOSL expression levels were determined by the fluorescence, reverse transcription PCR (RT-PCR) and Western blot, respectively. RESULTS: The ICOSL mRNA OD values of control and 100 mg/L ox-LDL group was 0.071+/-0.035 and 0.186+/-0.044, respectively. The Western blot A values of control and 100 mg/L ox-LDL group was 10.88+/-1.53 and 16.03+/-4.08, respectively. ox-LDL increased expression of ICOSL mRNA and protein(P<0.05). CONCLUSION: ICOSL can express on the HCAEC. ox-LDL can up-regulate the expression of ICOSL.

Identification of signaling pathways involved in aberrant production of adipokines in adipocytes undergoing oxidative stress.

BACKGROUND AND AIMS: In obesity, oxidative stress is responsible for the aberrant production of adipokines such as adiponectin, plasminogen activator inhibitor (PAI)-1 and interleukin-6 (IL-6), which is causally associated with obesity-related inflammation, insulin resistance and cardiovascular disease. However, the signaling transduction pathways participating in adipokine dysregulation induced by oxidative stress are largely unknown. Thus, the aim of the present study was to identify possible involved signaling pathways. METHODS: 3T3-L1 cells were differentiated into adipocytes and underwent oxidative stress by exposure to extraneous H(2)O(2). Quantitative PCR and immunoassays were performed to determine mRNA and protein levels of adipokines (adiponectin, PAI-1 and IL-6), respectively. Possible signaling pathways involved were high-throughout identified by Bioplex phosphoprotein assays and subsequently confirmed by inhibition of the targeted protein kinases such as Akt, ERK1/2, JAK/STAT, JNK, and p70 S6K, respectively. RESULTS: H(2)O(2) markedly suppressed adiponectin mRNA expression as well as protein secretion; however, it enhanced PAI-1 and IL-6 production in mature adipocytes. Akt,JAK/STAT and ERK1/2 participated in the H(2)O(2)-induced increase of PAI-1 and IL-6 expression, whereas adiponectin expression was reduced by H(2)O(2) via Akt and JAK/STAT. CONCLUSIONS: Akt and JAK/STAT are congenerous pathways through which oxidative stress downregulates adiponectin and upregulates PAI-1 and IL-6 expression. ERK1/2 participates not in H(2)O(2)-induced decrease of adiponectin expression, but in the increase of PAI-1 and IL-6.

Inhibition of cardiomyocyte contractile/relaxation by MN9202 and mechanisms involved.

BACKGROUND: The cardiac contractile function of hypertensive patients is higher than non-hypertensive patients so that it is beneficial for lowering cardiac contractile function of hypertensive patients. It remains unclear if MN9202, a dihydropyridine calcium channel blocker, has effects on positive inotropic responses induced by tetraethylammonium chloride (TEA), an antagonist of calcium-activated potassium channels, forskolin (FSK), an activator of adenylyl cyclase, isoproterenol (Iso), an activator of beta-adrenergic receptors, and methylene blue (MB), an inhibitor of guanylyl cyclase, in electrically stimulated rat cardiomyocytes. Myocyte shortening and intracellular calcium transients were assessed and the underlying mechanisms were investigated. METHODS: Twitch amplitude was measured by a video edge tracker method. Cell shortening/relengthening indexes including peak height (ph), peak height/baseline percent (ph/bl%), maximal velocity of shortening (+dL/dt), and maximal velocity of relengthening (-dL/dt) were recorded and analyzed by computer. Calcium transient amplitude (DeltaFFI) indicates intracellular calcium transients. RESULTS: Iso, FSK, TEA, and MB enhanced electrical stimulation induced contraction as evidenced by increased ph, ph/bl%, +/- dL/dt, and calcium transient amplitude (DeltaFFI) compared with those in the control group. Under basal conditions, MN9202 decreased electrically induced contraction (ph, ph/bl%,+dL/dt,-dL/dt) in a concentration-dependent manner from 3 x 10(-10) to 3 x 10(-6) mol/L. MN9202 significantly decreased calcium transient amplitude. Moreover, MN9202 (3 x 10(-6) mol/L) partially but significantly blocked the positive inotropic effect induced by Iso, FSK, MB, and TEA through blocking DeltaFFI. CONCLUSIONS: Iso, FSK, TEA, and MB increased the shortening and relengthening function of cardiomyocytes, which were partially blocked by MN9202. These results suggest that MN9202 may not only block the dihydropyridine receptor but may also inhibit other calcium influx. The exact mechanism of the action of MN9202 requires further study.

[Inhibitory effects of rosiglitazone against endothelin-1-induced proliferation of rat cardiac myocytes: the role of PKC-c-fos pathway].

OBJECTIVE: To investigate the mechanism of rosiglitazone (RSG, the activator of peroxisome proliferators activated receptor lambda) for inhibiting endothelin-1 (ET-1)-induced neonatal rat cardiac myocyte hypertrophy and the role of protein kinase C (PKC) and c-fos. METHODS: In vitro cultured neonatal rat cardiac myocytes were treated with ET-1, phorbol ester (PMA, the PKC activator), ET-1+RSG, ET-1+chelerythrine (che, the PKC inhibitor), PMA+RSG, or without treatment (control), respectively. The effects of RSG on the protein content, (3)H-leucine incorporation, PKC activity and C-fos protein expression were observed in the cardiac myocytes stimulated with ET-1 or PMA. RESULTS: After two days of culture, the intracellular protein content in ET-1 group and PMA group were increased by 15% (339-/+15 microg/ml) and 13% (329-/+14 microg/ml) as compared with the control cells (290-/+13 microg/ml), respectively (P<0.01). Compared with the ET-1 group, cells treated with ET-1+10(-8) mol/L RSG, ET-1+10(-7) mol/L RSG, and ET-1+che showed decreased intracellular protein content by 10% (303-/+14 microg/ml, P<0.05), 12% (292-/+11 microg/ml, P<0.05), and 13% (291-/+12 microg/ml, P<0.01), respectively. The intracellular protein content in PMA+10(-7) mol/LRSG group was decreased by 10% (P<0.05) in comparison with the PMA group. RSG inhibited protein synthesis enhancement and increased (3)H-leucine incorporation induced by ET-1 and PMA, and antagonized the effects of ET-1 and PMA in promoting PKC activity and c-fos protein expression in the myocytes. CONCLUSION: The inhibitory effect of RSG on ET-1- or PMA-induced myocyte hypertrophy is associated with PKC-c-fos pathway.

[Relationship between cardiomyocyte protein synthesis and cell viability].

OBJECTIVE: To observe the relationship between protein sythesis and cardiomyocyte viability in neonatal rats. METHODS: The protein sythesis in neonatal rat cardiomyocytes was measured according to Brandford's method, the absorbance at 490 nm (A(490 nm)) of the cells was measured with MTT assay and the cell viability evaluated by the ratio of A(490 nm) to the total cell number. RESULTS: ET-1 increased cardiomyocyte protein synthesis dose-dependently, and this effect was attenuated by the application of lacidipine and tetramethylpyrazines Higher doses of ET-1 resulted in lower A(490 nm)/total cell number ratio, which was further lowered by larcidipine and tetramethylpyrazine. CONCLUSION: The status of protein synthesis is not associated with the viability of neonatal rat cardiomyocytes.

[Analysis of inflammatory reaction of atherosclerosis model].

OBJECTIVE: To analysis and evaluate the inflammatory reaction of atherosclerosis model in rabbits. METHOD: A model of atherosclerosis in rabbits was estabalished by injury with balloon and high cholesterol diet to observe the dynamic change of serum inflammation markers c-reactive protein, interleukin-1beta and tumor necrosis factor-a, and the relationship between severity of AS lesion and those change. RESULT: (1) The levels of TNF-alpha at 4 time points: 1, 6, 10 weeks and 10 weeks + 1 day after balloon injury increased 1.6-fold, 2.2-fold, 4-fold, 2-fold over concurrent control, respectively (P < 0.05, P < 0.01, P < 0.01, P < 0.01), but no significant changes occurred during the observation. (2) At the end of the 6, 10 weeks and 10 weeks + 1 day, the levels of CRP were increased 3.5-fold, 3.6-fold, 3.0-fold than concurrent control (P < 0.01, P < 0.01, P < 0.01), respectively. The levels were increased 2.4-fold at the end of the 6 weeks and 4.1-fold at the end of the 10 weeks and reached the peak compared with the point of 1 week. (3) TNF-alpha and CRP showed a significant positive correlation with the MIT (correlation coefficients were found to be 0.61, 0.64, P < 0.01). (4) At the end of the 1, 6, 10 weeks, the model was provided with general pathological characteristics and the inflammatory reaction of earlier inflammatory reaction phase, fatty streak plaques phase, fibrous plaque phase respectively. CONCLUSION: The model was provided with early and medial phase typical feature of atherosclerotic lesion, and showed a significant positive correlation with the inflammatory factor expression. At the end of the 6 weeks, the formation of fatty streak plaques and obvious inflammatory reaction could be satisfied for the interference in forming process of AS from dimension of inflammatory and screening assays of drugs.

[Protective effects of nitric oxide donor on hydrogen peroxide-induced injury of cardiomyocytes].

To investigate the protective effects of nitric oxide (NO) on cardiomyocytes against hydrogen peroxide (H2O2)-induced injury, cultured neonatal cardiomyocytes were divided into three groups: (1) normal group; (2) H2O2 group: cells were treated with H2O2 (0.1 mmol/L) for 4 h; (3) SNAP+ H2O2 group: cells were pretreated with NO donor S-nitroso-N-acetyl-1,1-penicillamine (SNAP, 0.5 mmol/L) 10 min before H2O2 treatment. Colorimetric assay was used to detect cell viability and lactate dehydrogenase (LDH) activity to evaluate cell injury. Apoptotic rate of cardiomyocytes were determined by flow cytometer. Superoxide dismutase (SOD) activity and malonaldehyde (MDA) content were measured by colorimetric assay to evaluate cell antioxidant ability. Intracellular calcium was tested by laser confocal microscopy. The results showed that after treatment with H2O2, cell viability was significantly reduced to 58.3+/-7.6% compared with normal group (93.1+/-6.2 %). LDH activity and apoptotic rates were 1580.5+/-186.7 U/L and 26.4+/-5.7% respectively, significantly higher than that of normal group (631.4+/-75.6 U/L and 0). SNAP pretreatment markedly improved cell viability to 79.7+/-9.3% and reduced LDH activity and apoptotic rates to 957.8+/-110.9 U/L and 9.1+/-3.3%, respectively. Cells treated with H2O2 had a lower SOD activity of 14.73+/-1.68 NU/ml and a higher MDA content of (15.35+/-3.49) micromol/L compared with normal cells (19.67+/-0.85 NU/ml) and (6.95+/-0.83 micromol/L), respectively. Cells with SNAP pretreatment had a higher SOD activity of 21.36+/-3.11 NU/ml and a lower MDA content of 9.12+/-1.47 micromol/L compared with H2O2 group. Intracellular calcium content was reduced by SNAP administration while enhanced by H2O2. Pretreatment with SNAP could antagonize the effect of H2O2 of accelerating intracellular calcium content. Based on the results observed, it is concluded that NO donor SNAP may protect cardiomyocytes from being injured by H2O2. The underlying mechanisms may include improving cell antioxidant ability and reducing intracellular calcium overload.