Lipoamide dehydrogenase and diaphorase catalyzed conversion of some NO donors to NO and reduction of NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO).

One of the key functions of nitric oxide (NO) in human is to dilate blood vessels. We tested glycerol trinitrate (GTN) and other well-known NO donors together with those bearing a >C=N-OH group for possible conversion to NO (or nitrites, respectively) by diaphorase (DP) and lipoamide dehydrogenase (LAD). Both, DP and LAD were unable to convert formamidoxime (FAM), acetone oxime (AC), acetohydroxamic acid (AHA) and Nomega-hydroxy-L-arginine (L-NOHA).

Detection of a hypersialylated beta1 integrin endogenously expressed in the human astrocytoma cell line A172.

Gliomas are the most common deadly brain tumors. Human cerebral tumors express high level of alpha5beta1 integrins. As a potential new target, alpha5beta1 was investigated here in two human astrocytoma cell lines, A172 and U87MG.

Vasorelaxant activity of some oxime derivatives.

Several non-aromatic substituted oxime derivatives (formamidoxime, acetaldoxime, acetone oxime, acetohydroxamic acid, formaldoxime) function as vasorelaxant NO donors when added to precontracted aortic rings in vitro. This study was aimed to evaluate whether these substances posses vasodilator properties under in vivo conditions. We studied blood pressure changes elicited by administration of these compounds to conscious chronically catheterized Wistar rats in which endogenous NO synthesis was acutely inhibited by N(omega)-nitro-L-arginine methyl ester (L-NAME) pretreatment (30 mg/kg i.

Relaxant effect of oxime derivatives in isolated rat aorta: role of nitric oxide (NO) formation in smooth muscle.

Various oxime derivatives were evaluated as nitric oxide (NO) donors in arteries. Relaxation of rat aortic rings was used for bioassay of NO production, and electron paramagnetic resonance spectroscopy for demonstration of NO elevation. In rings with or without endothelium or adventitia, hydroxyguanidine and hydroxyurea were almost inactive, whereas formamidoxime, acetaldoxime, acetone oxime, acetohydroxamic acid and formaldoxime elicited relaxation.

Effect of drugs on cholesterol crystallization in an artificial bile model and relation of this effect to drug binding to albumin.

Substances that can affect the crystallization of cholesterol from human bile and consequently the gallstone formation have been given considerable attention. We improved the model system for testing cholesterol crystallization-affecting activity (promoting or inhibiting) of substances and used it for some drugs that are excreted into bile. Besides other factors natural lipid-protein complexes isolated from the native human bile have been shown to be responsible for nucleation and fast crystal growth in cholesterol supersaturated model bile.

Involvement of NO in the endothelium-independent relaxing effects of N(omega)-hydroxy-L-arginine and other compounds bearing a C=NOH function in the rat aorta.

The mechanisms of vasorelaxation elicited by N(omega)-hydroxy-L-arginine (L-NOHA) and other compounds bearing a C=NOH function and the structural determinants governing this effect were investigated in rat aorta. L-NOHA, formamidoxime, five aromatic monosubstituted amidoximes, and one aromatic monosubstituted ketoxime elicited relaxation in endothelium-denuded rings. N-Hydroxyguanidine and substituted N-hydroxyguanidines were markedly less active.