the no removal over oxide sorbents (k2o/al2o3 , cao/al2o3 and bao/al2o3) at a loading of up to 25 wt.% was investigated using a synthetic diesel exhaust gas containing  1,000 ppm no, 1000 ppm iso-butane (i-c4h10), 8% o2 and n2 balance. the reactor was operated  at 250 oc to 450 oc for the activity study. no was effectively stored (removal efficiencies between 30-60 %) as nitrate under experimen...

The 1998 Nobel Prize in Physiology or Medicine recognized the biological significance of nitric oxide. Nitric oxide is derived from the amino acid arginine. It is intimately involved with circulatory vessel dilation where, for example, it protects against heart attacks, and is the basis for new medications such as Sildenafil (Viagra). Nitric oxide acts as a neurotransmitter and can modulate man...

Purification of soluble guanylate cyclase from rat liver resulted in an apparent loss of enzyme activation by nitric oxide that could be restored by dithiothreitol. methemoglobin, bovine serum albumin, or sucrose. Although hemoglobin also permitted some activation with nitric oxide, the effect of other agents to restore enzyme activation was prevented with hemoglobin. As a result of enzyme puri...

nitric oxide is a short-lived mediator, which can be induced in a variety of cell types and produces many physiologic and metabolic changes in target cells. it is important in many biological functions and generated from l-arginine by the enzyme nitric oxide synthase. nitric oxide conveys a variety of messages between cells, including signals for vasorelaxation, neurotransmission and cytotoxici...

The roles of nitric oxide are primarily undefined in astrocytes, cells that are active partners in synaptic transmission. Because nitric oxide synthases are present in astrocytes, we imaged the formation of nitric oxide in cultured murine cortical astrocytes using DAF-FM (4-amino-5-methylamino-2',7'-difluorofluorescein diacetate). We demonstrated that physiological concentrations of ATP induced...

in this study we investigated the effects of endothelium removal and l-name on responses to α-adrenoceptor agonists. male wistar rats were killed by overdose with pentobarbitone sodium, after which the left and right common carotid arteries were removed. rings of arteries 3-4 mm in length were cut from each vessel and then mounted in 10 ml isolated organ bath, bathed in krebs maintained at 37°c...

were concentration-dependently relaxed by PGD2 (0.01-1 ,uM), a reaction that was blocked by a selective PGD receptor antagonist (BW A868C). There was a tight correlation between PGD2and acetylcholineinduced relaxations (r=0.894, n=96, p<0.001). Removal of endothelium abolished the PGD2-induced relaxation and unmasked a contractile activity of the compound. Inhibition of endogenous PGI2 formatio...

ischemia reperfusion injury (ir injury) is a common problem in clinical conditions. researches have frequently revealed that atp- sensitive potassium (katp) channels and nitric oxide plays a role in protection against ischemic injury in skeletal muscle. the present study aimed at evaluating the possible link between this two pathways. sixty-eight male wistar rats, were pretreated with saline, d...

background: during the initial phase of an infection, there is an upregulation of inducible nitric oxide synthase in the macrophages for the production of nitric oxide. this is followed by the recruitment of polymorphonuclear leukocytes (neutrophils) which release arginase. arginase competes with inducible nitric oxide synthase for a common substrate l-arginine. objective: to investigate whethe...

Chronic ethanol consumption is associated with an increased prevalence of hypertension. The mechanisms of this form of hypertension are unknown. Rats fed ethanol for 2 days develop a tolerance to the acute vasoconstrictive effects of ethanol that is believed to be endothelium dependent. We investigated the effects of acute and chronic ethanol exposure on agonist-stimulated nitric oxide synthase...