Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Formates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources
PubMed1989

Influence of the ion-pair-formation on the pharmacokinetic properties of drugs. Part 5: Influence of ion-pair-formation on elimination of bretylium and hexylsalicylic acid in rats.

Following i.v. administration of the hydrophilic drug bretylium (1) and the lipophilic hexylsalicylic acid (2) in rats the plasma levels of 2 were increased due to an increased intestinal reabsorption of 2. Under these conditions the biliary eliminated amount of 2 was 8 times higher than that following the administration of 2 alone. The eneteroheptic circulation of 2 was found to be interrupted following i.v. administration of 1 and 2 and additional oral administration of an anionic exchanger. Then the plasma levels of 2 were not influenced by 1. On other hand the plasma levels of 2 appear to be too low in order to influence those of 1.

Animals↗
PubMed1989

Oxidation of cycloalkylamines by cytochrome P-450. Mechanism-based inactivation, adduct formation, ring expansion, and nitrone formation.

Mechanism-based destruction of cytochrome P-450 (P-450) and P-450 heme is observed during the oxidation of N-cyclopropyl and N-cyclobutyl benzylamines. The slower inactivation by the cyclobutylamines relative to cyclopropylamines is consistent with known relative rates of ring opening of cycloalkyl-substituted aminium radicals. Evidence was found that porphyrin meso adducts of the type reported for horseradish peroxidase and cyclopropanone hydrate (Wiseman, J. S., Nichols, J. S., and Kolpak, M. X. (1982) J. Biol. Chem. 257, 6328-6332) were not formed. Radiolabels from cyclopropylamine substrates were covalently attached to protein but essentially only from the cyclopropyl portion and not the benzylic portion. Neither label appeared to be bound to extractable heme; however, during oxidations with cyclopropylamines, labeled P-450 heme became covalently attached to protein. Oxidation of 1-phenylcyclobutylamine by P-450 yielded 2-phenyl-1-pyrroline and 2-phenylpyrrolidine, and the ring expansion is interpreted as evidence for the existence of aminium radicals based on precedents with monoamine oxidase (Silverman, R. B., and Zieske, P. A. (1985) Biochemistry 24, 2128-2138). In addition, purified P-450PB-B oxidized N-(1-phenylcyclobutyl)-benzylamine to N-(1-phenyl)cyclobutyl phenyl nitrone, identified using spectral techniques. This transformation involves two sequential oxidations with either a hydroxylamine or benzylidene intermediate. While P-450 oxidized the amine to both compounds, only the hydroxylamine was rapidly oxidized to give the nitrone. The ring expansion and nitrone products are interpreted in the context of aminium radical intermediates involved in the mechanism of P-450-catalyzed amine oxidation.

Animals↗
PubMed1988

[Angiography in peripheral arterial occlusive disease. Comparison between large-format angiography, digital subtraction angiography and intermediate-format technic].

With peripheral venous injection of contrast medium, DSA serves to diagnose occlusive peripheral arterial disease in some 90% of cases. Indications for iv-DSA are occlusions and stenoses in the area of the iliac and femoral arteries, as well as in the proximal lower leg. Intraarterial DSA with fine needle is additionally indicated in some 10% of patients for examination of the distal lower leg arteries. In non-diagnostic DSA, conventional angiography using 100-mm technique may be performed with the same angiographic unit.

Angiography↗