Nitric oxide (NO) is emerging as an important regulator of bacterial stress resistance, biofilm development, and virulence. One potential source of endogenous NO production in the pathogen Staphylococcus aureus is its NO-synthase (saNOS) enzyme, encoded by the nos gene. Although a role for saNOS in oxidative stress resistance, antibiotic resistance, and virulence has been recently-described, in...

Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bin...

Nitric oxide (NO) synthesized from the inducible isoform of nitric oxide synthase (NOS-2) has been suggested to play both beneficial and deleterious roles in various neuropathologies. To define the role of nitric oxide in traumatic brain injury, we subjected male mice lacking a functional NOS-2 gene (NOS-2-/-) and their wild-type littermates (NOS-2+/+) to mild or severe aseptic cryogenic cerebr...

Much has been written about how effective nature of science instruction must have a significant explicit and reflective character. However, while explicitly drawing students’ attention to NOS issues is crucial, learning and teaching the NOS are essentially matters of conceptual change. In this article, how people learn and learners’ responses to the demands of conceptual change are used to expl...

For the extrapolation of data obtained from experimental animals to the human situation, it is important to know the similarities and differences between human and animal species. Some important characteristics of nitric oxide synthase (NOS) in myometrium and vagina from human and rat were compared. NOS-activity was measured by the formation of 14C-citrulline from 14C-arginine and the expressio...

Nitric oxide (NO) signaling regulates various physiological processes in both animals and plants. In animals, NO synthesis is mainly catalyzed by NO synthase (NOS) enzymes. Although NOS-like activities that are sensitive to mammalian NOS inhibitors have been detected in plant extracts, few bona fide plant NOS enzymes have been identified. We searched the data set produced by the 1000 Plants (1K...

We investigated the expression of nitric oxide synthase (NOS) isoforms -1, -2 and -3 in the retina and optic nerve head (ONH) in an experimental rat model of elevated intraocular pressure (IOP) before and after treatment with timolol, to assess whether its neuroprotective action is associated with the activity of these enzymes. Episcleral vein cauterization in unilateral eyes of Wistar rats was...

BACKGROUND Portal hypertension in cirrhosis results from enhanced intrahepatic resistance to an augmented inflow. The former is partly due to an imbalance between intrahepatic vasoconstriction and vasodilatation. Enhanced endothelin-1 and decreased activity of hepatic constitutive endothelial nitric oxide synthase (NOS 3) was reported in carbon tetrachloride (CCl(4)) cirrhotic rat liver. AIMS...

Brophy, Colleen M., Louis Knoepp, Jingdong Xin, and Jennifer S. Pollock. Functional expression of NOS 1 in vascular smooth muscle. Am. J. Physiol. Heart Circ. Physiol. 278: H991–H997, 2000.—Substances that increase intracellular calcium concentration ([Ca]i), such as serotonin, are known to induce vascular smooth muscle (VSM) contraction. However, increases in [Ca]i also activate Ca21/calmoduli...

Nanos (Nos) is one of the evolutionarily conserved proteins known to direct germ-line development. In Drosophila, maternal Nos protein maintains transcriptional quiescence in the germ-line progenitors or pole cells to repress ectopic expression of somatic genes. Here we show that maternal Nos is required to establish and maintain germ-line identity by preventing apoptosis and somatic cell fate....