67 research outputs found
Radiosensitization of hypoxic tumour cells by S-nitroso-N-acetylpenicillamine implicates a bioreductive mechanism of nitric oxide generation
The radiosensitizing activity of S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor, was assessed in a model of non-metabolic hypoxia achieved in an atmosphere of 95% nitrogen–5% carbon dioxide. A 10 min preincubation of hypoxic EMT-6 cells (10 × 106 ml−1) with 0.1 and 1 mM SNAP before radiation resulted in an enhancement ratio of 1.6 and 1.7 respectively. The level of spontaneous NO release, measured by a NO specific microsensor, correlated directly with the concentration of SNAP and was enhanced 50 times in the presence of cells. Dilution of the cell suspension from 10 to 0.1 × 106 ml−1 resulted in a 16-fold decline in NO release, but only a twofold decrease in radiosensitization was observed. Preincubation of hypoxic cells with SNAP for 3 min up to 30 min caused an increasing radiosensitizing effect. Extended preincubation of 100 min led to the loss of radiosensitization although the half-life of SNAP is known to be 4–5 h. Taken together, these observations suggest that SNAP generates NO predominantly by a bioreductive mechanism and that its biological half-life is unlikely to exceed 30 min. The lack of correlation between free NO radical and radiosensitizing activity may reflect a role of intracellular NO adducts which could contribute to radiosensitization as well. © 1999 Cancer Research Campaig
The myth of nitric oxide in central cardiovascular control by the nucleus tractus solitarii
Adenosine Kinase Inhibition Augments Conducted Vasodilation and Prevents Left Ventricle Diastolic Dysfunction in Heart Failure With Preserved Ejection Fraction
Comparison of Models Describing the Sorption of Nitroglycerin and Diazepam by Plastic Infusion Systems - Diffusion and Compartment Models
Factors Affecting the Availability of Diazepam Stored in Plastic Bags and Administered Through Intravenous Sets
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