Hepatic portal venous delivery of a nitric oxide synthase inhibitor enhances net hepatic glucose uptake

2008 ◽  
Vol 294 (4) ◽  
pp. E768-E777 ◽  
Author(s):  
Mary Courtney Moore ◽  
Catherine A. DiCostanzo ◽  
Marta S. Smith ◽  
Ben Farmer ◽  
Tiffany D. Rodewald ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
No Donor ◽  
Nitric Oxide Synthase Inhibitor ◽  
Significant Difference ◽  
Nos Inhibitors ◽  
Hepatic Glucose ◽  
Hepatic Portal ◽  
Oxide Synthase ◽  
Arterial Glucose

Hepatic portal venous infusion of nitric oxide synthase (NOS) inhibitors causes muscle insulin resistance, but the effects on hepatic glucose disposition are unknown. Conscious dogs underwent a hyperinsulinemic (4-fold basal) hyperglycemic (hepatic glucose load 2-fold basal) clamp, with assessment of liver metabolism by arteriovenous difference methods. After 90 min (P1), dogs were divided into two groups: control (receiving intraportal saline infusion; n = 8) and LN [receiving NG-nitro-l-arginine methyl ester (l-NAME), a nonspecific NOS inhibitor; n = 11] intraportally at 0.3 mg·kg−1·min−1 for 90 min (P2). During the final 60 min of study (P3), l-NAME was discontinued, and five LN dogs received the NO donor SIN-1 intraportally at 6 μg·kg−1·min−1 while six received saline (LN/SIN-1 and LN/SAL, respectively). Net hepatic fractional glucose extraction (NHFE) in control dogs was 0.034 ± 0.016, 0.039 ± 0.015, and 0.056 ± 0.019 during P1, P2, and P3, respectively. NHFE in LN was 0.045 ± 0.009 and 0.111 ± 0.007 during P1 and P2, respectively ( P < 0.05 vs. control during P2), and 0.087 ± 0.009 and 0.122 ± 0.016 ( P < 0.05) during P3 in LN/SIN-1 and LN/SAL, respectively. During P2, arterial glucose was 204 ± 5 vs. 138 ± 11 mg/dl ( P < 0.05) in LN vs. control to compensate for l-NAME's effect on blood flow. Therefore, another group (LNlow; n = 4) was studied in the same manner as LN/SAL, except that arterial glucose was clamped at the same concentrations as in control. NHFE in LNlow was 0.052 ± 0.008, 0.093 ± 0.023, and 0.122 ± 0.021 during P1, P2, and P3, respectively ( P < 0.05 vs. control during P2 and P3), with no significant difference in glucose infusion rates. Thus, NOS inhibition enhanced NHFE, an effect partially reversed by SIN-1.

Repeated treatment with nitric oxide synthase inhibitor attenuates learned helplessness development in rats and increases hippocampal BDNF expression

2017 ◽  
Vol 30 (3) ◽  
pp. 127-136 ◽  
Author(s):  
Laura Alves Stanquini ◽  
Caroline Biojone ◽  
Francisco Silveira Guimarães ◽  
Sâmia Regiane Joca
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Learned Helplessness ◽  
Positive Control ◽  
Repeated Treatment ◽  
Bdnf Expression ◽  
Nitric Oxide Synthase Inhibitor ◽  
Protein Levels ◽  
Nos Inhibitors ◽  
Oxide Synthase

BackgroundNitric oxide synthase (NOS) inhibitors induce antidepressant-like effects in animal models sensitive to acute drug treatment such as the forced swimming test. However, it is not yet clear if repeated treatment with these drugs is required to induce antidepressant-like effects in preclinical models.ObjectiveThe aim of this study was to test the effect induced by acute or repeated (7 days) treatment with 7-nitroindazole (7-NI), a preferential inhibitor of neuronal NOS, in rats submitted to the learned helplessness (LH) model. In addition, we aimed at investigating if 7-NI treatment would increase brain-derived neurotrophic factor (BDNF) protein levels in the hippocampus, similarly to the effect of prototype antidepressants.MethodsAnimals were submitted to a pre-test (PT) session with inescapable footshocks or habituation (no shocks) to the experimental shuttle box. Six days later they were exposed to a test with escapable footshocks. Independent groups received acute (a single injection after PT or before test) or repeated (once a day for 7 days) treatment with vehicle or 7-NI (30 mg/kg).ResultsRepeated, but not acute, treatment with 7-NI attenuated LH development. The effect was similar to repeated imipramine treatment. Moreover, in an independent experimental group, only repeated treatment with 7-NI and imipramine increased BDNF protein levels in the hippocampus.ConclusionThe results suggest the nitrergic system could be a target for the treatment of depressive-like conditions. They also indicate that, similar to the positive control imipramine, the antidepressant-like effects of NOS inhibition could involve an increase in hippocampal BDNF levels.

scholarly journals 7-Nitro indazole, a neuron-specific nitric oxide synthase inhibitor, produces amnesia in the chick.

1994 ◽  
Vol 1 (4) ◽  
pp. 213-216
Author(s):  
C Hölscher
Keyword(s):  
Nitric Oxide ◽  
Synaptic Plasticity ◽  
Nitric Oxide Synthase ◽  
Blood Vessel ◽  
Passive Avoidance ◽  
Avoidance Task ◽  
Nitric Oxide Synthase Inhibitor ◽  
Nos Inhibitors ◽  
Synthase Inhibitor ◽  
Oxide Synthase

7-Nitro indazole (7-NI), which is selective for the neuronal isoform of nitric oxide synthase (NOS), was tested in a passive avoidance task in the chick. Injection of 50 mg/kg i.p. pretraining had amnesic effects for the task when tested 30 min, 2 or 24 hr after training. Injections post-training had no effect. Because 7-NI does not inhibit the endothelial isoform of NOS, it does not affect blood vessel relaxation, as nonspecific inhibitors do. This effect on blood vessels could explain the amnestic effects produced by nonspecific NOS inhibitors. The results support the theory that NO is a neuronal transmitter that is important in processes of synaptic plasticity and learning.

Effect of nitric oxide synthase inhibitors on ovum transport and oviductal smooth muscle activity in the rat oviduct

Reproduction ◽  
2000 ◽  
pp. 111-117 ◽  
Author(s):  
S Perez Martinez ◽  
M Viggiano ◽  
AM Franchi ◽  
MB Herrero ◽  
ME Ortiz ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Fold Increase ◽  
Control Group ◽  
Pregnant Rats ◽  
No Donor ◽  
Nos Inhibitors ◽  
Ovum Transport ◽  
Egg Transport ◽  
Oxide Synthase

The effect of the inhibition of nitric oxide synthase (NOS) on ovum transport and oviductal motility in rats was investigated. Three different NOS inhibitors were injected into the ovarian bursa at oestrus or day 3 of pregnancy. Oviducts and uteri were flushed 24 h later and the presence of ova was recorded. In oestrous and pregnant rats, treatment resulted in accelerated egg transport, as shown by a decrease in the number of ova present in the oviducts. In cyclic rats, intrabursal injection of 1 mg kg-1 of either N-monomethyl-L-arginine (L-NMMA) or N omega nitro-L-arginine methyl ester (L-NAME) elicited a 30% reduction in the number of ova present in the oviducts, whereas in pregnant animals, the same dose of L-NMMA produced a reduction of 40%. Simultaneous administration of the NO donor spermine NONOate (5 mg kg-1) completely reversed the effect of L-NMMA. Tubal motility was assessed by microsphere displacement analysis within the oviduct. Surrogate ova were transferred to the oviductal lumen at oestrus and 24 h later the effect of intraoviductal injection of 1 microgram L-NMMA or vehicle was assessed. The microspheres in the isthmus showed an oscillating motion, and periods in which movement was not detectable. However, L-NMMA treatment produced a 3.6-fold increase in the maximum instant velocities and a significant reduction in the resting periods of the microspheres compared with the control group (P < 0.001). These results provide evidence that NO inhibition increases tubal motility that results in accelerated ovum transport, and indicate that NO could act as a paracrine signal between different layers of the oviductal wall, providing a role for endogenous NO in regulation of tubal function.

Nitric oxide acts independently of cGMP to modulate capacitative Ca2+ entry in mouse parotid acini

1999 ◽  
Vol 277 (2) ◽  
pp. C262-C270 ◽  
Author(s):  
Eileen L. Watson ◽  
Kerry L. Jacobson ◽  
Jean C. Singh ◽  
Sabrina M. Ott
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Guanylate Cyclase ◽  
Feedback Loop ◽  
Soluble Guanylate Cyclase ◽  
Complete Inhibition ◽  
No Donor ◽  
Nos Inhibitors ◽  
Induced Changes ◽  
Oxide Synthase

Carbachol- and thapsigargin-induced changes in cGMP accumulation were highly dependent on extracellular Ca2+ in mouse parotid acini. Inhibition of nitric oxide synthase (NOS) and soluble guanylate cyclase (sGC) resulted in complete inhibition of agonist-induced cGMP levels. NOS inhibitors reduced agonist-induced Ca2+ release and capacitative Ca2+ entry, whereas the inhibition of sGC had no effect. The effects of NOS inhibition were not reversed by 8-bromo-cGMP. The NO donor GEA-3162 increased cGMP levels blocked by the inhibition of sGC. GEA-3162-induced increases in Ca2+ release from ryanodine-sensitive stores and enhanced capacitative Ca2+ entry, both of which were unaffected by inhibitors of sGC but reduced by NOS inhibitors. Results support a role for NO, independent of cGMP, in agonist-mediated Ca2+release and Ca2+ entry. Data suggest that agonist-induced Ca2+influx activates a Ca2+-dependent NOS, leading to the production of NO and the release of Ca2+ from ryanodine-sensitive stores, providing a feedback loop by which store-depleted Ca2+ channels are activated.

scholarly journals Neuronal nitric oxide synthase regulation of calcium cycling in ventricular cardiomyocytes is independent of Cav1.2 channel modulation under basal conditions

2019 ◽  
Vol 472 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Janine Ebner ◽  
Michal Cagalinec ◽  
Helmut Kubista ◽  
Hannes Todt ◽  
Petra L. Szabo ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Single Channel ◽  
Neuronal Nitric Oxide Synthase ◽  
Inhibitory Effect ◽  
Open Probability ◽  
No Donor ◽  
Ventricular Cardiomyocytes ◽  
Nos Inhibitors ◽  
Oxide Synthase

AbstractNeuronal nitric oxide synthase (nNOS) is considered a regulator of Cav1.2 L-type Ca2+ channels and downstream Ca2+ cycling in the heart. The commonest view is that nitric oxide (NO), generated by nNOS activity in cardiomyocytes, reduces the currents through Cav1.2 channels. This gives rise to a diminished Ca2+ release from the sarcoplasmic reticulum, and finally reduced contractility. Here, we report that nNOS inhibitor substances significantly increase intracellular Ca2+ transients in ventricular cardiomyocytes derived from adult mouse and rat hearts. This is consistent with an inhibitory effect of nNOS/NO activity on Ca2+ cycling and contractility. Whole cell currents through L-type Ca2+ channels in rodent myocytes, on the other hand, were not substantially affected by the application of various NOS inhibitors, or application of a NO donor substance. Moreover, the presence of NO donors had no effect on the single-channel open probability of purified human Cav1.2 channel protein reconstituted in artificial liposomes. These results indicate that nNOS/NO activity does not directly modify Cav1.2 channel function. We conclude that—against the currently prevailing view—basal Cav1.2 channel activity in ventricular cardiomyocytes is not substantially regulated by nNOS activity and NO. Hence, nNOS/NO inhibition of Ca2+ cycling and contractility occurs independently of direct regulation of Cav1.2 channels by NO.

Role of nitric oxide synthase isoforms in glucose-stimulated insulin release

2002 ◽  
Vol 283 (1) ◽  
pp. C296-C304 ◽  
Author(s):  
Ragnar Henningsson ◽  
Albert Salehi ◽  
Ingmar Lundquist
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Insulin Release ◽  
Type Ii Diabetes Mellitus ◽  
No Production ◽  
No Donor ◽  
Nos Inhibitors ◽  
Constitutive Nitric Oxide Synthase ◽  
Oxide Synthase

The role of islet constitutive nitric oxide synthase (cNOS) in insulin-releasing mechanisms is controversial. By measuring enzyme activities and protein expression of NOS isoforms [i.e., cNOS and inducible NOS (iNOS)] in islets of Langerhans cells in relation to insulin secretion, we show that glucose dose-dependently stimulates islet activities of both cNOS and iNOS, that cNOS-derived nitric oxide (NO) strongly inhibits glucose-stimulated insulin release, and that short-term hyperglycemia in mice induces islet iNOS activity. Moreover, addition of NO gas or an NO donor inhibited glucose-stimulated insulin release, and different NOS inhibitors effected a potentiation. These effects were evident also in K+-depolarized islets in the presence of the ATP-sensitive K+ channel opener diazoxide. Furthermore, our results emphasize the necessity of measuring islet NOS activity when using NOS inhibitors, because certain concentrations of certain NOS inhibitors might unexpectedly stimulate islet NO production. This is shown by the observation that 0.5 mmol/l of the NOS inhibitor N G-monomethyl-l-arginine (l-NMMA) stimulated cNOS activity in parallel with an inhibition of the first phase of glucose-stimulated insulin release in perifused rats islets, whereas 5.0 mmol/l of l-NMMA markedly suppressed cNOS activity concomitant with a great potentiation of the insulin secretory response. The data strongly suggest, but do not definitely prove, that glucose indeed has the ability to stimulate both cNOS and iNOS in the islets and that NO might serve as a negative feedback inhibitor of glucose-stimulated insulin release. The results also suggest that hyperglycemia-evoked islet NOS activity might be one of multiple factors involved in the impairment of glucose-stimulated insulin release in type II diabetes mellitus.

Glomerular and tubular interactions between renal adrenergic activity and nitric oxide

1995 ◽  
Vol 268 (6) ◽  
pp. F1004-F1008 ◽  
Author(s):  
F. B. Gabbai ◽  
S. C. Thomson ◽  
O. Peterson ◽  
L. Wead ◽  
K. Malvey ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Glomerular Filtration ◽  
Renal Nerves ◽  
Ang Ii ◽  
Nitric Oxide Synthase Inhibitor ◽  
Adrenergic Activity ◽  
Single Nephron ◽  
Synthase Inhibitor ◽  
Oxide Synthase

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.

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