Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.99.1 (NADPH-diaphorase)
 3,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four chronic experiments were performed to assess changes in the activity and gene expression of type I nitric oxide synthase (NOS) at the macula densa (MD) and of renin expression and immunoreactivity (IR) at the juxtaglomerular apparatus (JGA) of rat kidney, as follows: 1) two-kidney, one-clip Goldblatt hypertension (2K1C, for 3 and 40 days; sham operation for controls), 2) furosemide treatment (150 mg/kg-1.day-1 ip for 5 days), 3) chronic low-salt diet (0.02%) vs. high-salt diet (3%; both for 11 days), and 4) chronic blockade of NOS by nitro-L-arginine methyl ester (L-NAME, 40 mg.kg-1.day-1 for 2 mo). NOS and renin gene expression, NOS enzyme activity and renin IR were semiquantitatively evaluated with histochemical methods (NADPH diaphorase, in situ hybridization, immunohistochemistry). In 2K1C, marked increases were induced in NOS and renin in the ischemic vs. contralateral kidneys both after 3 and 40 days, respectively (P < 0.05). Related to controls, significant increases in the ischemic kidney were encountered after 3 and 40 days, whereas contralateral suppression of NOS and renin was found only after 40 days. Furosemide treatment resulted in a marked increase of both NOS and renin levels compared with controls (P < 0.05). Salt restriction induced a significant elevation of NOS levels compared with salt loading (P < 0.05), whereas only minor changes were evident in renin levels. L-NAME treatment resulted in a moderate reduction of NOS activity (not significant), whereas renin levels were markedly reduced (P < 0.05). These results show that NOS activity and gene expression are inversely related to chronic changes in renal perfusion, salt balance, and salt transport at the distal tubule in parallel with the known response of renin to these changes. Inhibition of NOS decreases renin levels at the JGA. The histochemical findings support previous concepts that MD-derived NO is involved in the control of renin synthesis.
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PMID:Parallel regulation of constitutive NO synthase and renin at JGA of rat kidney under various stimuli. 859 73

In the kidney, nitric oxide (NO) from the macula densa (MD) is considered an integral modulator of the tubulovascular message system, whereas endothelium-derived NO is a major vasorelaxing factor. The goal of the present study was to determine extracellular pathways of NO in rats with renovascular two-kidney, one clip Goldblatt hypertension (2K1C). To localize NO in the tissue, immunohistochemical detection of NO-dependent tyrosine nitration was performed using a monoclonal antibody against nitrotyrosine. Nitration of phenolic compounds such as tyrosine results from the reaction with peroxynitrite (ONOO ) formed by NO and molecular oxygen or superoxide and may therefore be used as a footprint for local release of NO. Significant nitrotyrosine immunoreactivity was detected in the extraglomerular mesangium (EGM) of the stenotic kidney in 2K1C rats, whereas in the nonclipped contralateral kidney and in control animals no signal was detected at this site. Positive staining of the EGM was paralleled by enhanced NADPH diaphorase (NADPH-d) staining of the adjacent MD, signifying increased type I nitric oxide synthase (NOS) activity in the stenotic kidney. In contrast, in the cortical vasculature selectively enhanced nitrotyrosine immunoreactivity was detected in the arteriolar wall of the nonclipped contralateral kidney, and endothelial NADPH-d signal, indicating NOS Type III activity, was enhanced in parallel. Our results suggest that in MD, stimulation of NOS in the stenotic Goldblatt kidney induces the release of NO into the EGM. From there an NO-dependent intermediate stimulus may reach the glomerular vasculature. Footprints of NO-dependent effects in the vascular smooth muscle layer of the non-clipped contralateral kidney indicate a marked vasodilatory response that may have been caused by enhanced shear stress and/or angiotensin II levels.
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PMID:Immunohistochemically detected protein nitration indicates sites of renal nitric oxide release in Goldblatt hypertension. 933 98