Thenitricoxidesynthases (NOS)area familyof relatedenzymeswhich regulate the production of NO, a free radical gas Implicated in a wide variety of biological processes.Vasodilatlon and increased tumor blood flow, increasedvascularpermeability,modulationof host tumoricidal activity, and free radical injury to tumor cells and adjacent normal tissues are pathophyslological features of malignant tumo...

Skeletal muscle and myocardium express microNOS I, an elongated splice variant of neuronal-type nitric oxide (NO) synthase (NOS I), and NOS III, endothelial-type NO synthase, respectively. This study was designed to elucidate whether vascular smooth muscle also contains a constitutively expressed NO synthase isoform. In the rat, microNOS I contains an insert of 102 nucleotides after nucleotide ...

OBJECTIVES The purpose of the present study was to examine the expression of the endothelial-type nitric oxide synthase (NOS III) and the inducible-type NOS (NOS II) in human myocardium and their regulation in heart failure from patients with different etiologies. BACKGROUND In heart failure, plasma levels of nitrates were found to be elevated. However, data on myocardial NOS expression in he...

Nanos (Nos) has at least five different functions during the development of Drosophila melanogaster. In the pre-cellular blastoderm embryo, maternally derived Nos is required for formation of abdominal segments (Wang and Lehmann, 1991). Subsequently, maternal Nos is required in the embryonic germline precursors, the pole cells, to inhibit their division and promote migration into the somatic go...

The nitric oxide synthases (NOS) are a family of related enzymes which regulate the production of NO, a free radical gas implicated in a wide variety of biological processes. Vasodilation and increased tumor blood flow, increased vascular permeability, modulation of host tumoricidal activity, and free radical injury to tumor cells and adjacent normal tissues are pathophysiological features of m...

Experiments were performed to quantify nitric oxide synthase (NOS) activity and identify the NOS isoforms present in the Sprague-Dawley rat renal vasculature. NOS enzymatic activity was measured by adding [(3)H]arginine to microdissected renal blood vessels and quantifying the conversion to [(3)H]citrulline by reverse-phase high-performance liquid chromatography. Total NOS activity was greatest...

This study examined the effects of acute exercise on skeletal muscle nitric oxide synthase (NOS) activity. Female Sprague-Dawley rats were divided into three groups: control, exercise, and exercise + N G-nitro-l-arginine methyl ester (l-NAME). In the exercise + l-NAME group, l-NAME was administered in the drinking water (1 mg/ml) for 2 days and subsequently the exercise and exercise + l-NAME gr...

Atrial natriuretic peptide (ANP) is an important regulator of blood pressure (BP). One of the mechanisms whereby ANP impacts BP is by stimulation of nitric oxide (NO) production in different tissues involved in BP control. We hypothesized that ANP-stimulated NO is impaired in the kidneys of spontaneously hypertensive rats (SHR) and this contributes to the development and/or maintenance of high ...

Whereas altered nitric oxide (NO.) formation from endothelial nitric oxide synthase (NOS) causes impaired vascular reactivity in a number of cardiovascular diseases, questions remain regarding how endothelial injury results in impaired NO. formation. It is unknown if loss of NOS expression or activity is required or if other factors are involved. Detergent treatment has been used to induce endo...