ANG II stimulates endothelial nitric oxide synthase expression in bovine pulmonary artery endothelium

1997 ◽  
Vol 273 (2) ◽  
pp. L315-L321 ◽  
Author(s):  
S. C. Olson ◽  
T. A. Dowds ◽  
P. A. Pino ◽  
M. T. Barry ◽  
T. Burke-Wolin

Although angiotensin II (ANG II) is a known pulmonary vasoconstrictor, the purpose of this study was to examine the effect of ANG II on pulmonary artery endothelial cell nitric oxide synthase (ecNOS) mRNA and protein expression. Cultured bovine pulmonary artery endothelial (BPAE; passages 5-8) cells were incubated for 0-12 h with 10(-6) M ANG II. Total RNA was extracted, and ecNOS expression was assessed by Northern blot analysis. In BPAE cells, ecNOS mRNA was significantly increased 2.4 +/- 0.3-fold (P < 0.05 vs. basal; n = 5) 6 h after the addition of ANG II over basal levels. In & similar time course, it was found that ecNOS protein concentrations are increased 247 +/- 62% (P < 0.05 vs. basal; n = 8) over basal levels 4 h after ANG II addition. There is a second protein peak 8 h after ANG II addition in which ecNOS was increased 333 +/- 145% over basal (P < 0.05, n = 3). These data suggest that ANG II stimulates ecNOS mRNA expression and are followed by increased levels of ecNOS protein in cultured BPAE cells, consistent with an observed increase in nitrite production. Both the increase in ecNOS protein and mRNA expression could be inhibited with the ANG II receptor antagonist saralasin. Additionally, actinomycin D, an inhibitor of transcription, prevented the rise in mRNA at 6 h while cycloheximide inhibited the initial protein peak. The effects of ANG II on ecNOS were specific for the pulmonary artery endothelium. Addition of ANG II did not increase ecNOS protein or mRNA expression in parallel studies in bovine coronary artery endothelium. The stimulation of ecNOS by ANG II may act to protect the lung and maintain low pulmonary artery pressures in the renin-angiotensin model of systemic hypertension.

Endocrinology ◽  
2015 ◽  
Vol 156 (7) ◽  
pp. 2657-2666 ◽  
Author(s):  
Takaichi Suehiro ◽  
Kazuhiko Tsuruya ◽  
Hirofumi Ikeda ◽  
Jiro Toyonaga ◽  
Shunsuke Yamada ◽  
...  

Chronic inhibition of nitric oxide synthase by Nω-nitro-L-arginine methyl ester (L-NAME) causes progressive renal injury and systemic hypertension. Angiotensin II (Ang II) has been conventionally regarded as one of the primary causes of renal injury. We reported previously that such renal injury was almost completely suppressed by both an Ang II type I receptor blocker and an aldosterone antagonist. The aldosterone antagonist also inhibited the systemic Ang II elevation. Therefore, it remains to be elucidated whether Ang II or aldosterone directly affects the development of such renal injury. In the present study, we investigated the role of aldosterone in the pathogenesis of renal injury induced by L-NAME-mediated chronic nitric oxide synthase inhibition in male Wistar rats (aged 10 wk). Serial analyses demonstrated that the renal injury and inflammation in L-NAME-treated rats was associated with elevation of both Ang II and aldosterone. To investigate the direct effect of aldosterone on the renal injury, we conducted adrenalectomy (ADX) and aldosterone supplementation in L-NAME-treated rats. In ADX rats, aldosterone was undetectable, and renal injury and inflammation were almost completely prevented by ADX, although systemic and local Ang II and blood pressure were still elevated. Aldosterone supplementation reversed the beneficial effect of ADX. The present study indicates that aldosterone rather than Ang II plays a central and direct role in the pathogenesis of renal injury by L-NAME through inflammation, independent of its systemic hemodynamic effects.


1999 ◽  
Vol 134 (5) ◽  
pp. 471-477 ◽  
Author(s):  
Kobi Sade ◽  
Doron Schwartz ◽  
Yoram Wolman ◽  
Idit Schwartz ◽  
Tamara Chernichovski ◽  
...  

2002 ◽  
Vol 103 (s2002) ◽  
pp. 289S-293S ◽  
Author(s):  
Zen-Kong DAI ◽  
Mian-Shin TAN ◽  
Chee-Yin CHAI ◽  
Ing-Jun CHEN ◽  
Arco Y. JENG ◽  
...  

The purpose of the study was to assess whether increased pulmonary flow and subsequent development of pulmonary vascular remodelling could alter the expression of endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) in the rat lung. Nine 42-day-old Wistar rats underwent abdominal aortocaval shunt to increase pulmonary blood flow for 12 weeks. The shunt resulted in significant medial hypertrophy of pulmonary artery without significant alterations in pulmonary or systemic blood pressure. Using competitive reverse transcription–PCR, significant increases in the preproET-1 mRNA expression and eNOS mRNA expression in the lungs of rats with abdominal aortocaval shunt were detected. Increased eNOS protein in the lung of shunt rats was also found by Western blot analysis. However, the plasma ET-1 concentration in the pulmonary artery (sham: 5±0.7pg/ml; shunt: 6±0.8pg/ml) or the lung ET-1 content (sham: 218±41ng/g protein; shunt: 224±40ng/g protein) was unchanged. There was an elevated immunohistochemical expression of eNOS, but not ET-1, in the pulmonary vascular endothelium in rats with the shunt. These results suggest that eNOS and ET-1 may be involved in remodelling prior to the development of pulmonary hypertension.


1995 ◽  
Vol 268 (6) ◽  
pp. F1004-F1008 ◽  
Author(s):  
F. B. Gabbai ◽  
S. C. Thomson ◽  
O. Peterson ◽  
L. Wead ◽  
K. Malvey ◽  
...  

Endothelium-dependent nitric oxide (EDNO) exerts control over the processes of glomerular filtration and tubular reabsorption. The importance of the renal nerves to the tonic influence of EDNO in the glomerular microcirculation and proximal tubule was tested by renal micropuncture in euvolemic adult male Munich-Wistar rats. The physical determinants of glomerular filtration and proximal reabsorption were assessed before and during administration of the nitric oxide synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA), in control animals and in animals 5–9 days after either ipsilateral surgical renal denervation (DNX) or after either sham surgery (SHX). L-NMMA caused single-nephron glomerular filtration rate to decline in control and SHX animals but not in DNX rats. L-NMMA caused a reduction in proximal reabsorption in control and SHX rats, which was prevented by prior DNX. DNX did not alter urinary guanosine 3',5'-cyclic monophosphate excretion, and, although DNX upregulates glomerular angiotensin II (ANG II) receptors, prior DNX did not alter intrarenal ANG II content as evaluated by radioimmunoassay. Some component of renal adrenergic activity is required for the full expression of the glomerular and tubular effects of blockade of nitric oxide synthase.


Nitric Oxide ◽  
2001 ◽  
Vol 5 (2) ◽  
pp. 208-211 ◽  
Author(s):  
Jean-Charles Preiser ◽  
Haibo Zhang ◽  
Bernard Vray ◽  
Andreas Hrabak ◽  
Jean-Louis Vincent

2002 ◽  
Vol 92 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Daniel Nyhan ◽  
Soonyul Kim ◽  
Stacey Dunbar ◽  
Dechun Li ◽  
Artin Shoukas ◽  
...  

Vascular contractile hyporesponsiveness is an important mechanism underlying orthostatic intolerance after microgravity. Baroreceptor reflexes can modulate both pulmonary resistance and capacitance function and thus cardiac output. We hypothesized, therefore, that pulmonary vasoreactivity is impaired in the hindlimb-unweighted (HLU) rat model of microgravity. Pulmonary artery (PA) contractile responses to phenylephrine (PE) and U-46619 (U4) were significantly decreased in the PAs from HLU vs. control (C) animals. N G-nitro-l-arginine methyl ester (10−5 M) enhanced the contractile responses in the PA rings from both C and HLU animals and completely abolished the differential responses to PE and U4 in HLU vs. C animals. Vasorelaxant responses to ACh were significantly enhanced in PA rings from HLU rats compared with C. Moreover, vasorelaxant responses to sodium nitroprusside were also significantly enhanced. Endothelial nitric oxide synthase (eNOS) and soluble guanlyl cyclase expression were significantly enhanced in PA and lung tissue from HLU rats. In marked contrast, the expression of inducible nitric oxide synthase was unchanged in lung tissue. These data support the hypothesis that vascular contractile responsiveness is attenuated in PAs from HLU rats and that this hyporesponsiveness is due at least in part to increased nitric oxide synthase activity resulting from enhanced eNOS expression. These findings may have important implications for blood volume distribution and attenuated stroke volume responses to orthostatic stress after microgravity exposure.


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