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Adventitia plays an important role in vascular injury diseases. Nitric oxide (NO) from inducible nitric oxide synthase (iNOS) is involved in many cardiovascular diseases. iNOS/NO pathway is activated in aorta of spontaneously hypertensive rats (SHRs). The role of aldosterone in L-arginine (L-Arg)/iNOS/NO pathway of aortic adventitia is uncertain. We investigated the effect of aldosterone antagonist spironolactone on adventitial L-Arg/iNOS/NO pathway in SHRs.Twenty male SHR (10 weeks old, 220-280 g) were randomly divided into 2 groups (10 in each): untreated or treated with the aldosterone receptor antagonist, spironolactone (20 mg/kg per day) for 6 weeks. Age-matched Wistar-Kyoto rats (WKY) were used as control. Systolic blood pressure (tail-cuff method) was measured weekly. Six weeks later, the rats were sacrificed. The whole aorta was collected and aortic adventitia was isolated. iNOS activity, [(3)H]-L-Arg transport assay of aortic adventitia were carried out by isotope-labeled L-arginine conversion rate measurement, and measurement of nitrate/nitrite (NOx), an index of NO production of aortic adventitia was assayed with the Griess reaction.iNOS activity, [(3)H]-L-Arg transport and NO production were greatly increased in aortic adventitia of SHR [(12.55 +/- 2.27) pmol x mg(-1) x min(-1), (0.88 +/- 0.19) pmol x mg(-1) x min(-1) and (2.07 +/- 0.39) micromol/L)] compare versus WKY [(5.96 +/- 1.87) pmol x mg(-1) x min(-1), (0.51 +/- 0.15) pmolxmg(-1) x min(-1) and (1.55 +/- 0.32) micromol/L, P0.01], and decreased significantly by spironolactone treatment [(8.32 +/- 1.84) pmol x mg(-1) x min(-1), (0.61 +/- 0.15) pmol x mg(-1) x min(-1) and (1.64 +/- 0.27) micromol/L, P0.01].L-Arg/iNOS/NO is activated in aortic adventitia of SHR. Spironolactone can inhibit the activation of L-Arg/iNOS/NO pathway. Aldosterone may play an important role in some cardiovascular diseases such as atherosclerosis through iNOS/NO pathway.

To investigate the effects of hydrogen sulfide (H2S) on vascular inflammation in pulmonary hypertension induced by high pulmonary blood flow.Forty-four male SD rats were randomly divided into 8 groups: 4-week control group (n = 7), 4-week shunt group (n = 7), 4-week shunt + propargylglycine (PPG, an endogenous H2S release inhibitor) intraperitoneal injection group (n = 8), 11-week control group (n = 7), 11-week shunt group (n = 7), and 11-week shunt + sodium hydrosulfide (NaHS, a H2S donor) intraperitoneal injection group (n = 8). Right ventricular catheterization was used to measure the mean pulmonary arterial pressure (mPAP). Immunohistochemistry was used to detect the expression of inflammatory related factor intercellular adhesion molecule-1 (ICAM-1), and the key molecules of nuclear factor-kappaB (NF-kappaB) signal transduction pathway, including NF-kappaB p65 and inhibitor of NF-kappaB (IkappaBalpha), in the pulmonary artery, and ELISA was used to detect the concentrations of the inflammatory related factors, including ICAM-1, interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) in blood plasma and lung tissues so as to reflect the corresponding inflammatory responsiveness.The plasma and lung tissue ICAM-1, IL-8 and MCP-1 contents of the 4-week shunt group were all significantly higher than those of the 4-week control group (P0.05 or P0.01). The mPAP of the 4 week shunt + PPG group was (20.3 +/- 1.7) mm Hg, significantly higher than that of the 4-week shunt group [(16.2 +/- 1.5) mm Hg, P0.01]. The expression levels of ICAM-1 and NF-kappaB p65 in the small and median pulmonary artery endothelin cells of the 4-week shunt + PPG group were both significantly stronger than those of the 4-week shunt group (P0.05 or P0.01), whereas the expression of IkappaBalpha was weaker than that of the 4-week shunt group (P0.05). The plasma IL-8 content of the 4-week shunt + PPG group was (148 +/- 29) micromol/L, significantly higher than that of the 4 week-shunt group [(118 +/- 23) micromol/L, P0.05], and the lung tissue ICAM-1 and MCP-1 levels of the 4-week shunt + PPG group were (27.3 +/- 5.0) micromol/g and (12.9 +/- 1.1) micromol/g respectively, both significantly higher than those of the 4-week shunt group [(21.9 +/- 2.1) and (10.2 +/- 1.4) micromol/g respectively, both P0.05]. The mPAP and expression levels of ICAM-1 and NF-kappaB p65 of the large, median, and small pulmonary artery endothelia cells of the 11-week shunt group were all higher than those of the 11-week control group (P0.05 or P0.01), whereas the expression levels of IkappaBalpha were all less obvious (P0.05 or P0.01). The plasma and lung tissue ICAM-1, IL-8, and MCP-1 levels of the 11-week shunt group were all significantly higher than those of the 11-week control group (all P0.01). The mPAP of the 11 week shunt + NaHS group was (23.2 +/- 3.0) mm Hg, significantly lower than that of the 11-week shunt group [(27.5 +/- 1.9) mm Hg, P0.05]. The ICAM-1 and NF-kappaB p65 expression levels of large, median, and small pulmonary artery endothelia cells of the 11-week shunt + NaHS group were all significantly weaker than those of the 11-week shunt group (P0.05 or P0.01), whereas the protein expression levels of IkappaBalpha in small and median pulmonary artery endothelia cells of the 11-week shunt + NaHS group were significantly higher than those of the 11-week shunt group (both P0.05). The plasma and lung tissue ICAM-1 contents of the 11-week shunt + NaHS group were (124 +/- 11) micromol/L and (19.9 +/- 2.5) micromol/g, both significantly lower than those of the 11-week shunt group [(154 +/- 20) micromol/L and (23.9 +/- 3.6) micromol/g respectively, both P0.01]. The plasma and lung tissue IL-8 contents of the 11-week shunt + NaHS group were (92 +/- 11) micromol/L and (15.0 +/- 1.7) micromol/g, both significantly lower than those of the 11-week shunt group [(121 +/- 17) micromol/L and (19.0 +/- 3.9) micromol/g respectively, both P0.01]. The lung tissue MCP-1 content of the 11-week shunt + NaHS group was (10.8 +/- 1.6) micromol/g, significantly lower than that of the 11-week shunt group [(13.5 +/- 1.4) micromol/g, P0.01].H2S attenuates the development of pulmonary hypertension induced by high pulmonary blood flow through ameliorating pulmonary vascular inflammation. The inhibitory effect of H2S on the pulmonary vascular inflammation involves elevating IkappaBalpha expression, down-regulating NF-kappaB p65 expression and then inhibiting the expression of inflammatory related factors.

To explore the effects of sulfur dioxide (SO2) on the proliferation and apoptosis of aorta smooth muscle cells in hypertension rats and possible mechanism thereof.Sixteen 4-week-old male spontaneously hypertensive rats (SHRs) were randomly divided into 2 equal groups: control and Na2SO3/NaHSO3 (a SO2 donor)-treated group. Eight 4-week-old male WKY (Wistar Kyoto) rats were assigned for normal control group. Five weeks later, the pressure was measured. The rat aortas were dyed with Hart's method. The morphometric parameters were calculated by Leica workstation. The plasma level of SO2 was determined by HPLC method. VSMC apoptosis was measured by TUNEL technique. The expression levels of proliferating cell nuclear antigen (PCNA), Bcl-2, Fas and caspase-3 were detected by immunohistochemical assay.(1) Compared with those of the WKY rats, the blood pressure, ratio of media to lumen radius, and proliferation index (PI) of the SHRs were increased [(172 +/- 10) mm Hg vs (112 +/- 9) mm Hg, 0.073 +/- 0.004 vs 0.057 +/- 0.004, 0.32 +/- 0.06 vs 0.05 +/- 0.03, respectively], but the plasma level of SO2 and the apoptosis index (AI) were decreased in the SHRs [(6.4 +/- 1.5) micromol/L vs (11.3 +/- 1.0) micromol/L, 0.16 +/- 0.07 vs 0.30 +/- 0.19, respectively]. The expression of Bcl-2 was increased (0.209 +/- 0.007 vs 0.202 +/- 0.006), and the expression levels of Fas and caspase-3 of SHRs were both lower than those of the WKY rats (0.205 +/- 0.006 vs 0.211 +/- 0.005, 0.229 +/- 0.005 vs 0.244 +/- 0.010, respectively). (2) Compared with the SHR control group, the systolic blood and the ratio of media to lumen radius were decreased [(128 +/- 7) mm Hg, 0.066 +/- 0.002, respectively], but the plasma level of SO2 was increased [(8.3 +/- 1) micromol/L] for the SHR + Na2SO3/NaHSO3 group. PI was lower (0.14 +/- 0.03) and AI was higher (0.40 +/- 0.11) in SHR + Na2SO3/NaHSO3 group than those in SHR control group. The expression of Bcl-2 of VSMCs was down-regulated (0.199 +/- 0.006), but the levels of Fas and caspase-3 were up-regulated (0.218 +/- 0.003 and 0.251 +/- 0.011 respectively) in the SHR + Na2SO3/NaHSO3 group.SO2 may attenuate the structural remodeling through reducing the proliferation and enhancing the apoptosis of smooth muscle cells in SHRs. SO2 may modulate the process of apoptosis possibly through the downward regulation of the level of Bcl-2 and enhance the expression of Fas and caspase-3.

To observe the effects of sulfur dioxide (SO2) on cardiac function of isolated perfused heart of rat and to explore the physiological regulation of endogenous SO2 on myocardial action.The hearts of 64 Wistar rats were isolated, perfused with Krebs-Henseleit (KH) solution through Langendorff apparatus, and randomly divided into 8 equal groups: Four groups underwent perfusion of SO2 of the concentrations 1, 10, 100, 1000 micromol/L respectively for 5 min and then perfused with KH solution for 15 min. Eight hearts underwent perfusion of SO2 of the physiological concentration (10 micromol/L) for 20 min. The control group underwent perfusion of KH solution for 20 min. Eight hearts of the nicardipine group underwent perfusion of nicardipine, a L-type calcium channel blocker, 2.5 micromol/L for 5 min, SO2 10 micromol/L for 5 min, and then KH solution for 10 min. The heart in the hydroxamate (HDX) group underwent perfusion of HDX, an inhibitor of SO2 endogenous generating enzymes, for 5 min, and then perfused by KH solution for 15 min. The heart rate (HR), difference of left ventricular pressure (LVP), left ventricular peak rate of contraction (+ dp/dtmax), peak rate of relaxation (- dp/dtmax), and coronary flow (CF) were measured. Then transmission electron microscopy was conducted.SO2 concentration-dependently inhibited the left ventricular +/- dp/dtmax, LVP, HR, and CF (all P0.01). The left ventricular +/- dp/dtmax, LVP, and HR were inhibited (P0.05) by the physiological concentration (10 micromol/L) SO2 donor continuous perfusion for 20 min. During perfusion 20 min, the LVP, + dp/dtmax, - dp/dtmax, and HR after perfusion for 20 min of the physiological concentration (10 micromol/L) SO2 donor continuous perfusion group were (15 +/- 3) mm Hg, (485 +/- 74) mm Hg/s, (339 +/- 64) mm Hg/s, and (114 +/- 26)/min respectively, all significantly lower than those 5 min after perfusion [(23 +/- 7) mm Hg, (595 +/- 93)mm Hg/s, (436 +/- 83) mm Hg/s, and (159 +/- 31)/min, all P0.05]. The LVP, + dp/ dtmax, -dp/dtmax, and HR of the nicardipine group were(37 +/- l0)mm Hg, (1025 +/- 287)mm Hg/s, (570 +/- 181)mm Hg/s, and (139 +/- 48)/min respectively, all not significantly different from those of the control group. The LVP, + dp/dtmax, - dp/dtmax, and CF after perfusion of the HDX group were (50 +/- 11)mm Hg, (1167 +/- 270) mm Hg/s, (889 +/- 72) mm Hg/s, and (6.3 +/- 1.9) ml/min respectively, all significantly lower than those before perfusion [(69 +/- 16) mm Hg, (1579 +/- 315) mm Hg/s, (1186 +/- 263) mm Hg/s, and (9.5 +/- 1.3) ml/min, all P0.05].Exogenous SO2 has negative inotropic effect on myocardium. by the mechanism related to voltage-gated calcium channel. Nicardipine blocks the inhibitory effect of SO2 at physiological concentration.

To explore the impact of endogenous hydrogen sulfide (H(2)S), a novel gaseous signal molecule, on the nitric oxide (NO)/nitric oxide synthase (NOS) pathway in left-to-right shunt.Thirty-two male SD rats were randomly divided into 4 equal groups: shunt group undergoing abdominal aorta-inferior vena cava puncture so as to establish model of left-to-right shunt; shunt + PPG group undergoing abdominal aorta-inferior vena cava puncture so as to establish model of left-to-right shunt and then intraperitoneal injection of propargylglycine (PPG), an inhibitor of cystathionine-gamma-lyase: sham group undergoing sham operation; and sham + PPG group undergoing sham operation and then intraperitoneal injection of PPG. Four weeks later, right cardiac catheterization was conducted to measure the mean pulmonary artery pressure (MPAP). Then the rats were killed and their lung tissues and samples of plasma were collected. The contents of H(2)S, nitric oxide (NO), and nitrogen oxide synthase (NOS) activity, and the content of plasma NO were calculated. Western blotting was used to detect the endothelial nitric oxide synthase (eNOS) protein in the lung tissues. The correlation of MPAP with lung H(2)S and NO was analyzed.The MPAP of the shunt group was not significantly different from that of the sham group, and the MPAP of the shunt + PPG group was significantly higher then those of the shunt group and sham group by 15.82% and 20.55% respectively (both P0.05). The content of lung tissue H(2)S of the shunt group was 37.56 +/- 2.13 micromol/mg, significantly higher than that of the shunt group (14.35 +/- 1.76, P0.05), the content of lung tissue H(2)S of the shunt + PPG group was 28.76 +/- 2.24 micromol/mg, significantly lower than that of the shunt group (P0.05). The lung tissue NO content of the shunt group was 38.48 micro +/- 6.53 micromol/microg, significantly higher than that of the sham group (31.78 +/- 6.51 micromol/microg). The NOS activity of the shunt group was 15.12 +/- 2.44 U/mg protein, significantly higher than that of the sham group (12.00 +/- 1.40 U/mg protein, P0.05). The lung eNOS content of the shunt group was significantly higher than that of the sham group (P0.05). The plasma NO content of the shunt group was 23.18 +/- 3.56 micromol/L, significantly higher than that of the sham group (17.94 +/- 3.39 micromol/L, P0.05). The lung tissues NO and NOS activity, and plasma NO of the shunt + PPG group were 46.04 +/- 5.95 micromol/microg, 20.89 +/- 3.94 U/mg protein, and 27.79 +/- 4.82 micromol/L respectively, all significantly higher than those of the shunt group (38.48 +/- 6.53 micromol/microg, 15.12 +/- 2.44 U/mg protein, and 23.18 +/- 3.56 micromol/L, all P0.05). The eNOS content of the shunt + PPG group was significantly higher than that of the shunt group (P0.05). The lung H(2)S content was negatively correlated with the MPAP and lung NO content (r = -0.705, P = 0.005; and r = -0.645, P = 0.013).Endogenous H(2)S may play a regulatory role in the pulmonary artery pressure of left-to-right shunt through inhibiting NO/NOS pathway.

To investigate the effects of oxidized-low density lipoprotein (ox-LDL) and urotensin II (U II) on the proliferation of rat aortic smooth muscle cells (VSMCs) and the effect of ox-LDL on the mRNA expression of U II receptor GPR14 in.Rat VSMCs were incubated with UII and ox-LDL at different concentrations. The viability of rat VSMCs was detected by MTT assay. Rat VSMCs were incubated with ox-LDL at the concentrations of 0, 0.1, 1, 10, and 50 microg/ml. Twelve hours later competitive RT-PCR was used to detect the effects of concentration of ox-LDP on the mRNA expression of GPR14 in the VSMCs. Another VSMCs were incubated with ox-LDL at the final concentration of 50 microg/ml, and 0, 2, 6, 12, and 24 hours later competitive RT-PCR was used to detect the mRNA expression of GPR14 in the VSMCs. (125)I-labelled U II was added into the culture fluid of VSMCs, and radioligand binding assay was used to calculate the maximum binding (B(max)).UII of the concentration of 50 nmol/L significantly increased the proliferation of VSMCs. When the concentration of ox-LDL was 10 microg/ml the proliferation of VSMCs (P0.01) was 0.678 +/- 0.061, increased by 121% compared with the control group (0.325 +/- 0.052, P0.01). 0.01 microg/ml of ox-LDL and 10 nmol/L of UII showed a synergistic effect on the proliferation of VSMCs with the MTT value increased to 162% +/- 29% that of the control group (P0.01). When the concentration of ox-LDL increase to 0.1 microg/ml the synergistic effect was attenuated with the MTT value of 153% +/- 22% that of the control group (P0.05) and when the concentration of ox-LDL increased to 1 microg/ml the synergistic effect diminished, with a MTT value of 123% +/- 13% that of the control group (P0.05). When the concentration of ox-LDL was 50 microg/ml the proliferation of VSMCs the MTT value decreased to 59% that of the of control group, however, ox-LDL of the concentration of 50 microg/ml combined with UII of the concentration of 10 nmol/L the MTT value increased to 68% that of the control group, showing that UII of that concentration significantly inhibited the cytotoxic effect of ox-LDL. Incubation of VSMCs with the ox-LDL at the concentration of 0.1 microg/ml the GPR14 mRNA expression of the VSMCs was 125.1% that of the control group (P0.01) as assessed by competitive RT-PCR, however, when the concentration of ox-LDL increased over 1 microg/ml the GPR14 mRNA expression does-dependently decreased as much as 72.6% that of the control group (all P0.01), with the maximal effect when the concentration of ox-LDL reached 50 microg/ml. ox-LDL at the concentration of 50 microg/ml time-dependently down-regulated the GPR14 mRNA expression with the maximal effect 12 hours after addition of ox-LDL and this effect was sustained for up to 24 hours. After incubation for 12 hours the binding of (125)I-UII to VSMCs was 117.5% that of the control group (P0.01) with the ox-LDL at the concentration of 0.1 microg/ml, and was 68.8% that of the control group (P0.01) with the ox-LDL at the concentration of 50 microg/ml.ox-LDL and with U-II. GPR14 at certain concentrations show synergetic effects on the proliferation of VSMCs. The GPR14 mRNA expression in VSMCs can be upregulated by low concentration of ox-LDL, while downregulated by high concentration of ox-LDL.