BACKGROUND The role of endothelial nitric oxide synthase 3 (NOS-3) in the hyperdynamic circulation associated with cirrhosis is established but not that of the neuronal (NOS-1) isoform. We therefore investigated aortic NOS-1 levels in NOS-3 knock-out (KO) and wildtype (WT) mice and in hepatic arteries of patients. METHODS Mice rendered cirrhotic by bile duct ligation (BDL) were compared with ...

Nitric oxide (NO), an important messenger molecule with widespread actions, is synthesized by NO synthases (NOS). In this study, we investigated the correlation between fiber type and NOS activity among ventilatory and limb muscles of various species. We also assessed the presence of the three NOS isoforms in normal skeletal muscles and how various NOS inhibitors influence muscle NOS activity. ...

In the adult central nervous system, nitric oxide (NO) is formed from L-arginine by the so-called constitutive or type I NO synthase (NOS-I155). However, expression of NOS-I155 immunoreactivity and activity was low or not detectable in developing mouse and rat brain. NOS-I155 was sharply induced coincident with the onset of synaptogenesis in specific brain regions. This was followed by a second...

Although neurotrophins are best known for their trophic functions, growing evidence suggests that neurotrophins can also be neurotoxic, for instance by enhancing excitotoxic insults. We have shown recently that brain-derived neurotrophic factor (BDNF) limits its neuroprotective action on axotomized rat retinal ganglion cells (RGCs) by upregulating nitric oxide synthase (NOS) activity (Klöcker e...

The development of a functional germline is essential for species propagation. The nanos (nos) gene plays an evolutionarily conserved role in germline development and is also essential for abdominal patterning in Drosophila. A small fraction of nos mRNA is localized to the germ plasm at the posterior pole of the Drosophila embryo, where it becomes incorporated into the germ cells. Germ plasm as...

Dysregulation of kidney nitric oxide synthase (NOS) I may alter renal hemodynamics in diabetes. Four types of studies were performed in anesthetized 1- to 2-wk-streptozotocin diabetic rats. 1) Glomerular filtration rate (GFR) was measured before and during NOS I blockade. Subsequent addition of nonspecific NOS blocker tested for residual NO from other isoforms. Acute systemic NOS I blockade red...

The expression of a primary initiator of tumor angiogenic responses, vascular endothelial growth factor (VEGF), may be induced by nitric oxide (NO) in carcinoma cells. However, the net impact of NO on carcinogenesis remains unclear, because manipulation of NO levels has been shown to either stimulate or inhibit tumor growth. We have investigated the relationship between inducible NO synthase (N...

ALTHOUGH NITRIC OXIDE SYNTHASES (NOSs) were first described in 1989 (12), these complex enzymes are still not fully understood, and their role in human lung disease remains unclear. Three NOS isoforms have been described in humans: neuronal or nNOS (NOS-1), inducible or iNOS (NOS-2), and endothelial or eNOS (NOS-3). All isoforms of NOS are modular enzymes with a reductase domain and an oxygenas...