Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.6.99.1 (NADPH-diaphorase)
3,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histochemistry for NADPH-diaphorase detects an enzymatic activity associated with nitric oxide synthase while immunohistochemistry detects the nitric oxide synthase molecule. NADPH-diaphorase and inducible isoform of nitric oxide synthase in Leydig cells in vitro and in testis sections of the bank vole were demonstrated histochemically and immunocytochemically. Histochemical studies revealed localization of NADPH-diaphorase reaction product in the cytoplasm of cultured Leydig cells as well as in the interstitial area, mainly in Leydig cells and in vascular endothelium. Distribution pattern of NADPH-diaphorase was different in Leydig cell cytoplasm of individual cells. Using immunocytochemistry, the immunoreactivity for nitric oxide synthase was observed both in cultured Leydig cells and testis sections. Moreover, a co-localization of positively immunostained cells with those histochemically detected was noticed. Addition of hCG to the cultured medium or injections in vivo resulted in a small decrease in reaction intensity in Leydig cells. Treatment with N omega-nitro-L-arginine methyl ester resulted in distinctly weaker reactivity of the enzymes studied which was correlated with a higher testosterone and estradiol levels in Leydig cells measured radioimmunologically. The results have indicated that nitric oxide synthase is able to act directly within the male gonad regulating androgen secretion by Leydig cells.
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PMID:Correlation between NADPH-diaphorase and iNOS in bank vole Leydig cells in vitro and in testicular sections with the use of histochemistry and immunocytochemistry. 1083 71

Conjugated estrogens shorten the prolonged bleeding time in uremic patients and are similarly effective in a rat model of uremia. We have previously demonstrated that the shortening effect of a conjugated estrogen mixture or 17beta-estradiol on bleeding time was abolished by the nitric oxide (NO) precursor L-arginine, suggesting that the effect of these drugs on hemostasis in uremia might be mediated by changes in the NO synthetic pathway. The present study investigated the biochemical mechanism(s) by which conjugated estrogens limit the excessive formation of NO. 17beta-estradiol (0.6 mg/kg), given to rats made uremic by reduction of renal mass, significantly reduced bleeding time within 24 h and completely normalized plasma concentrations of the NO metabolites, nitrites and nitrates, and of NO synthase (NOS) catalytic activity, determined by NADPH-diaphorase staining in the thoracic aorta. Endothelial NOS (ecNOS) and inducible NOS (iNOS) immunoperoxidase staining in the endothelium of uremic aortas of untreated rats was significantly more intense than in control rats, while in uremic rats receiving 17beta-estradiol staining was comparable to controls. Thus 17beta-estradiol corrected the prolonged bleeding time of uremic rats and fully normalized the formation of NO by reducing the expression of ecNOS and iNOS in vascular endothelium. These results provide a possible biochemical explanation of the well-known effect of estrogens on primary hemostasis in uremia, in experimental animals and humans.
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PMID:17beta-estradiol corrects hemostasis in uremic rats by limiting vascular expression of nitric oxide synthases. 1099 12

Nitric oxide (NO) is a novel gaseous intercellular transmitter thought to play important physiological roles in the regulation of blood flow and hormone secretion in, for example, the pituitary, the thyroid, and the endocrine pancreas. Whether nitric oxide synthase (NOS) is present in the human parathyroid glands has not yet been demonstrated. In the present study, histologically normal, but functionally suppressed human parathyroid glands and parathyroid adenomas from patients with primary hyperparathyroidism were investigated by immunocytochemistry with antibodies against neuronal NOS and by reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry. We also used H&E to identify the NOS-immunoreactive cells. Immunocytochemistry demonstrated the presence of neuronal-type NOS in a subpopulation of glandular cells, identified as oxyphilic cells, in both normal parathyroid glands and adenomas. NADPH-diaphorase staining visualized NOS in the endothelium of blood vessels and in glandular cells, corresponding to those containing immunoreactive NOS. In addition, we found NADPIH-diaphorase staining in many chief cells. Our results indicate that both glandular cells and vascular endothelium in human parathyroid glands and adenomas express NOS. There is thus a morphological substrate for locally produced NO that may be involved in the regulation of parathyroid blood flow and hormone secretion.
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PMID:Nitric Oxide Synthase in Human Parathyroid Glands and Parathyroid Adenomas. 1211 33

Nitric oxide (NO) signalling pathways were examined in the lateral aortae and dorsal aorta of the cane toad Bufo marinus. NADPH diaphorase histochemistry and nitric oxide synthase (NOS) immunohistochemistry found no evidence for endothelial NOS in the endothelium of toad aortae, but it could be readily demonstrated in rat aorta that was used as a control. Immunohistochemistry using a specific neural NOS antibody showed the presence of neural NOS immunoreactivity in the perivascular nerves of the aortae. The anatomical data was supported by in vitro organ bath physiology, which demonstrated that the vasodilation mediated by applied acetylcholine (10(-5) mol l(-1)) was not dependent on the presence of the vascular endothelium; however, it was significantly reduced in the presence of a neural NOS inhibitor, vinyl-L-NIO (10(-4) mol l(-1)). In addition, atropine (10(-6) mol l(-1)) (a muscarinic receptor inhibitor), L-NNA (10(-4) mol l(-1)) (a NOS inhibitor) and ODQ (10(-5) mol l(-1)) (an inhibitor of soluble guanylyl cyclase) abolished the vasodilatory effect of applied acetylcholine. In conclusion, we propose that an endothelial NO system is absent in toad aortae and that NO generated by neural NOS in perivascular nerves mediates vasodilation.
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PMID:Nitric oxide regulation of the central aortae of the toad Bufo marinus occurs independently of the endothelium. 1220 Apr 12

Ischemic preconditioning (IPC) may protect the liver from ischemia reperfusion injury by nitric oxide formation. This study has investigated the effect of ischemic preconditioning on hepatic microcirculation (HM), and the relationship between nitric oxide metabolism and HM in preconditioning. Rats were allocated to 5 groups: 1. sham laparotomy; 2. 45 minutes lobar ischemia followed by 2-hour reperfusion (IR); 3. IPC with 5 minutes ischemia and 10 minutes reperfusion before IR; 4. L-arginine before IR; and 5. L-NAME + IPC before IR. HM was monitored by laser Doppler flowmeter. Liver transaminases, adenosine triphosphate, nitrites + nitrates, and guanosine 3'5'-cyclic monophosphate (cGMP) were measured. Nitric oxide synthase (NOS) distribution was studied using nicotinamide adeninine dinucleotide phosphate (NADPH) diaphorase histochemistry. At the end of reperfusion phase, in the IR group, flow in the HM recovered partially to 25.8% of baseline (P < .05 versus sham), whereas IPC improved HM to 49.5% of baseline (P < .01 versus IR). With L-arginine treatment, HM was 31.6% of baseline (NS versus IR), showing no attenuation of liver injury. In the preconditioned group treated with L-NAME, HM declined to 10.2% of baseline, suggesting not only a blockade of the preconditioning effect, but also an exacerbated liver injury. Hepatocellular injury was reduced by IPC, and L-arginine and was increased by NO inhibition with L-NAME. IPC also increased nitrate + nitrate (NOx) and cGMP concentrations. NOS detected by NADPH diaphorase staining was associated with hepatocytes and vascular endothelium, and was induced by IPC. IPC induced NOS and attenuated HM impairment and hepatocellular injury. These data strongly suggest a role for nitric oxide in IPC.
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PMID:Effect of ischemic preconditioning on hepatic microcirculation and function in a rat model of ischemia reperfusion injury. 1247 59

NADPH-diaphorase (NADPH-d) and an inducible type of nitric oxide synthase (iNOS) were demonstrated in porcine ovaries after unilateral infusion of bacteria into the hilus of an ovary. In group I one ml of saline was infused into the hilus of each ovary from the 15th day to the 19th day of the estrous cycle. In group II one ml of bacterial suspension (10(9) colony forming units of Escherichia coli, Staphylococcus aureus and Corynebacterium pyogenes, in a proportion 1:1:1, respectively) in saline was infused into the hilus of one ovary on days corresponding to those of the control group (gr. I), whereas saline was infused into the contralateral ovary. The ovaries were collected on the 7th day of the next estrous cycle. In the bacteria-treated ovary, the activity of NADPH-d was higher in the endothelium of blood vessels, corpora lutea and follicular walls in comparison to that observed in the respective structures of the contralateral ovary. The highest activity of NADPH-d was found in the vascular endothelium in the bacteria-infused ovary. Vascular smooth muscle cells found in both ovaries of the bacteria-treated gilts were more intensely stained for NADPH-d than those in control animals. After bacteria administration, the intensity of NADPH-d reaction in all the structures of both ovaries in group II was higher than in control group. The strongest immunostaining for iNOS was observed in all structures of the bacteria-infused ovary. In the contralateral ovary, iNOS-immunoreactivity was weaker but still stronger than that in control group. The present results revealed that infusions of bacteria into the hilus of one ovary enhanced the activity of NADPH-d and immunoreactivity for iNOS in both porcine ovaries. However, the activity of both enzymes was higher in the bacteria-infused ovary than in the contralateral one. These data suggest that locally synthesized NO can mediate an inflammatory effect of bacteria in the porcine ovaries.
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PMID:Involvement of nitric oxide in inflammation of ovaries in gilts. 1466 63

This study investigated the nature of vasodilator mechanisms in the dorsal aorta of the giant shovelnose ray, Rhinobatus typus. Anatomical techniques found no evidence for an endothelial nitric oxide synthase, but neural nitric oxide synthase was found to be present in the perivascular nerve fibres of the dorsal aorta and other arteries and veins using both NADPH-diaphorase staining and immunohistochemistry with a specific neural NOS antibody. Arteries and veins both contained large nNOS-positive nerve trunks from which smaller nNOS-positive bundles branched and formed a plexus in the vessel wall. Single, varicose nNOS-positive nerve fibres were present in both arteries and veins. Within the large bundles of both arteries and veins, groups of nNOS-positive cell bodies forming microganglia were observed. Double-labelling immunohistochemistry using an antibody to tyrosine hydroxylase showed that nearly all the NOS nerves were not sympathetic. Acetylcholine always caused constriction of isolated rings of the dorsal aorta and the nitric oxide donor, sodium nitroprusside, did not mediate any dilation. Addition of nicotine (3 x 10(-4) M) to preconstricted rings caused a vasodilation that was not affected by the nitric oxide synthase inhibitor, L-NNA (10(-4) M), nor the soluble guanylyl cyclase inhibitor, ODQ (10(-5) M). This nicotine-mediated vasodilation was, therefore, not due to the synthesis and release of NO. Disruption of the endothelium significantly reduced or eliminated the nicotine-mediated vasodilation. In addition, indomethacin (10(-5) M), an inhibitor of cyclooxygenases, significantly increased the time period to maximal dilation and reduced, but did not completely inhibit the nicotine-mediated vasodilation. These data support the hypothesis that a prostaglandin is released from the vascular endothelium of a batoid ray, as has been described previously in other groups of fishes. The function of the nitrergic innervation of the blood vessels is not known because nitric oxide does not appear to regulate vascular tone.
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PMID:Vasodilator mechanisms in the dorsal aorta of the giant shovelnose ray, Rhinobatus typus (Rajiformes; Rhinobatidae). 1472 May 87

The presence of nitric oxide synthase (NOS) was investigated in the ventricle of two Antarctic teleosts, the hemoglobinless icefish Chionodraco hamatus and its red-blooded counterpart, Trematomus bernacchii. Under unstimulated conditions, in both teleosts, NADPH-diaphorase localised NOS activity in the endocardial-endothelial cells (EEc) and in the myocardiocytes. Application of anti-mammalian endothelial and inducible NOS (eNOS and iNOS, respectively) primary antibodies for immunofluorescence revealed a comparable tissue-specific basal expression of the two isoforms in the two species. eNOS strongly localised at the level of the EEc and, in T. bernacchii, of the vascular endothelium (VE). The enzyme is also localised, albeit to less extent, within the myocardiocytes, and in the epicardium. In contrast, iNOS immunostaining only labels the cytoplasm of the ventricular myocytes. Western blotting analysis identified two peptides with molecular masses of about 135 and 130kDa, similar to those of the mammalian eNOS and iNOS. To verify whether this NOS system is susceptible to septic stimulation, C. hamatus and T. bernacchii were exposed to bacterial lipopolysaccharides (LPS). The treatment did not modify the distribution pattern of the two isoenzymes while it increased the amount of NADPH-diaphorase-dependent reaction product and the expression of both eNOS and iNOS. These results indicate a high phylogenetic conservation of the intracardiac NOS system, emphasizing its importance in the control of the vertebrate heart and its relevance as a general mechanism of defense against pathogens.
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PMID:Cardiac expression and distribution of nitric oxide synthases in the ventricle of the cold-adapted Antarctic teleosts, the hemoglobinless Chionodraco hamatus and the red-blooded Trematomus bernacchii. 1691 89

We investigated co-adaptation of enzymatic systems of cells using data on activity of NAD(Ph)-dependent enzymes and AgNOR proteins of vascular endothelium vis-a-vis angiogenesis in benign and malignant smooth muscle tumors of the corpus uteri. Overall metabolic activity (NAD-H2 diaphorase) was found to directly correlate with angiogenesis and endothelial vessel proliferation (r = 0.76 and 0.84, respectively). SDH-regulated oxidation in the main metabolic succession of a tricarbonic acid cycle depended on blood supply and endothelial vessel proliferation (r = 0.84 and 0.92, respectively; p = 0.04). A similar relationship was shown for anaerobic glycolysis of SDH (LDH content), on the one hand, and blood supply and endothelial vessel proliferation(r = 0.57 and 0.70, respectively; p = 0.02), on the other. Hence, metabolic profile varied in unaltered myometrium and tumor with variable cellular density and peculiar extracellular matrix. The highest levels of metabolic activity with NAD(Ph)-dependent enzyme co-adaptation was observed in sarcomas which were also characterized by the highest vascular density for endothelial proliferation.
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PMID:[Co-adaptation of enzymatic systems of cells and blood supply in smooth muscle tumors of the corpus uteri]. 1906 75

The aim of the present study was to investigate the localization and expression of NADPH-diaphorase (NADPH-d) as well as endothelial (eNOS) and inducible (iNOS) nitric oxide synthase isoforms in the porcine uterus on Days 20, 30, 40, 60, 75 and 90 of gestation. The significant increase (p<0.001) in NADPH-d reaction was found in the trophoblast. The positive NADPH-d staining was also observed in the luminal and glandular epithelium and vascular endothelium. eNOS immunoreactivity was found in the endothelium of placental and maternal blood vessels, in the luminal epithelium and endometrial glands. The trophoblast displayed a slight increase in eNOS immunoreactivity starting from Day 20 of gestation. In comparison to eNOS, a stronger iNOS staining was found in the placental and endometrial blood vessels and in the trophoblast cells. Western blot analysis revealed a gradual increase in eNOS protein expression from Day 30 (p<0.001) and iNOS from Day 60 of gestation (p<0.001) in the placental zone. The significant increase in the NADPHd/iNOS expression after day 60 of gestation suggests a contribution of iNOS in uterine NO generation during the second half of pregnancy. A gradual increase in eNOS expression starting on Day 30 of pregnancy may indicate a synergistic, supportive effect on uterine vascular and myometrial contractility in pigs affecting the maintenance of the uterine quiescence.
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PMID:The localization and expression of NADPH-diaphorase and isoforms of nitric oxide synthase in the porcine gravid uterus. 1909 87


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