Nitric Oxide Synthase Type I

Nitric oxide (NO) triggers multiple signal transduction pathways and contributes to the control of numerous cellular functions. Previous studies have shown in model organisms that the alteration of NO production has important effects on aging and lifespan. We studied in a large sample (763 subjects, age range 19-107†years) the variability of the three human genes (NOS1, -2, -3) coding for the three isoforms of the NADPH-dependent enzymes named NO synthases (NOS) which are responsible of NO synthesis.

ETHNOPHARMACOLOGICAL RELEVANCE: Withania somnifera (WS) root extract has been used traditionally in ayurvedic system of medicine as a memory enhancer and anti-stress agent. AIM OF THE STUDY: To evaluate the neuroprotective and prophylactic potential of WS root extract in ameliorating hypobaric hypoxia (HH) induced memory impairment and to explore the underlying molecular mechanism. MATERIALS AND METHODS: WS root extract was administered to male Sprague Dawley rats during a period of 21 days pre-exposure and 07 days exposure to a simulated altitude of 25,000 ft.

We hypothesized that elevated partial pressures of O(2) would increase perivascular nitric oxide (*NO) synthesis. Rodents with O(2)- and.NO-specific microelectrodes implanted adjacent to the abdominal aorta were exposed to O(2) at partial pressures from 0.2 to 2.8 atmospheres absolute (ATA). Exposures to 2.0 and 2.8 ATA O(2) stimulated neuronal (type I) NO synthase (nNOS) and significantly increased steady-state.NO concentration, but the mechanism for enzyme activation differed at each partial pressure.

The purpose of this study was to examine cardiovascular responses to fourth cerebral ventricle (4V) administration of nitroglycerin (NTG) or an inhibitor of nitric oxide (NO) synthase (NOS) in the near-term ovine and to determine whether, during birth, neuronal NOS (nNOS) is induced in noradrenergic A1 neurons in the medial nucleus tractus solitarius (mNTS). In chronically instrumented fetal sheep, 4V injection of NTG (1.2 nmol), an NO donor, produced an arterial blood depressor and a moderate decrease in heart rate.

The purpose of these studies was to determine the role of gracile nucleus and the effects of l-arginine-derived nitric oxide (NO) synthesis in the nucleus on the cardiovascular responses to electroacupuncture (EA) stimulation of "Zusanli" (ST36). Arterial blood pressure and heart rate were monitored during EA stimulation of ST36 following microinjections of agents into gracile nucleus. EA ST36 produced depressor and bradycardiac responses in anesthetized Sprague-Dawley rats.

The present study was to examine the distribution of transient receptor potential vanilloid type-1 (TRPV1) receptor immunoreactivity in the acupuncture points (acupoint), and determine the influences of electroacupuncture (EA) stimulation on TRPV1 expression. EA stimulation of BL 40 was conducted in two sessions of 20 min separated by an 80 min interval in anesthetized rats. Sections of skin containing BL 40, and its non-meridian control were examined by immunolabeling with antibodies directed against TRPV1.

BACKGROUND: Nitric oxide (NO) is implicated in the pathogenesis of irritable bowel syndrome (IBS) but the underlying mechanism is unclear. Thus, the aim of the present study is to examine the role of NO synthase (NOS) expression in the distal colon of neonatal maternal separation (NMS) model rats employed in IBS studies. METHODS: Male neonates of Sprague-Dawley rats were randomly assigned into NMS and normal control (N) groups. Rats of NMS group were subjected to 3 h daily maternal separation on postnatal day 2-21.

The role of taurine in regulating glucose-induced nitrosative stress has been examined in human Schwann cells, a model for understanding the pathogenesis of diabetic neuropathy. Exposure to high glucose increased nitrated proteins (1.56 fold p<0.05), inducible nitric oxide synthase (iNOS) and neuronal NOS (nNOS) mRNA expression (1.55 fold and 2.2 fold respectively, p<0.05 both), phospho-p38 MAPK (1.32 fold, p<0.05) abundance and decreased Schwann cell growth (11±2%, p<0.05).

Immune complexes composed of IgG-opsonized pathogens, particles, or proteins are phagocytosed by macrophages through Fcγ receptors (FcγRs). Macrophages primed with IFNγ or other pro-inflammatory mediators respond to FcγR engagement by secreting high levels of cytokines and nitric oxide (NO). We found that unprimed macrophages produced lower levels of NO, which required efficient calcium (Ca(2+)) flux as demonstrated by using macrophages lacking selenoprotein K, which is required for FcγR-induced Ca(2+) flux.

BACKGROUND: Duchenne muscular dystrophy (DMD) is the most common, lethal disease of childhood. One of 3500 new-born males suffers from this universally-lethal disease. Other than the use of corticosteroids, little is available to affect the relentless progress of the disease, leading many families to use dietary supplements in hopes of reducing the progression or severity of muscle wasting. Arginine is commonly used as a dietary supplement and its use has been reported to have beneficial effects following short-term administration to mdx mice, a genetic model of DMD.