Library

X
Language
Preferred search index
Number of Hits per Page
Default Sort Criterion
Default Sort Ordering
Size of Search History
Default Email Address
Default Export Format
Default Export Encoding
Facet list arrangement
Maximum number of values per filter
Auto Completion
Feed Format
Maximum Number of Items per Feed
Permalink If you want to be able to use settings permanently, you must save your settings and then set a Bookmark to the permalink
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Selective Effect of Adjuvant Arthritis on the Disposition of Propranolol Enantiomers in Rats Detected Using a Stereospecific HPLC Assay (1993)
    Springer
    Pharmaceutical research 10 (1993), S. 294-299 
    Details
    ISSN: 1573-904X
    Keywords: propranolol ; inflammation ; stereoselective ; adjuvant arthritis ; enantiomer ; HPLC ; pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nonstereospecific studies have indicated that the pharmacokinetics of propranolol (PR) are altered in inflammatory conditions such as arthritis. However, as the kinetics and dynamics of PR are stereoselective, we examined the effect of adjuvant arthritis (AA) on the disposition of the individual enantiomers. A novel normal-phase stereospecific HPLC assay for PR was developed involving chiral derivatization with S-(naphthyl)ethyl isocyanate and fluorescence detection. Oral and iv doses of racemic PR were administered to control and AA rats (n = 6). AA had no significant effect on either clearance or S:R ratio after iv doses. On the other hand, after oral doses, clearance was significantly decreased in AA. Although significant for both enantiomers, this effect was more pronounced on the less active R-enantiomer. The AUC R:S ratio was, therefore, significantly altered (AA, 14 ± 3.0; control, 4.3 ± 1.2). Increased total (S + R) plasma concentrations of PR in AA, possibly due to a reduced intrinsic clearance, therefore, reflect mainly increased concentrations of the less active R-enantiomer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018907431893
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Characterization of Guanidine Transport in Human Renal Brush Border Membranes (1997)
    Springer
    Pharmaceutical research 14 (1997), S. 936-941 
    Details
    ISSN: 1573-904X
    Keywords: brush-border membrane vesicles ; organic cation transport ; tetraethylammonium ; guanidine ; human kidney ; transporters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. Organic cation transporters in the renal proximal tubule are important in the secretion of many clinically used drugs and their metabolites. The goal of this study was to determine the mechanisms of guanidine transport in human kidney. Methods. Brush-border membrane vesicles were prepared from donor human kidneys deemed unsuitable for renal transplantation. Results. Uptake of [14C]-guanidine (50 μM) in the vesicles, as determined by rapid filtration, was significantly greater in the presence of an outwardly-directed proton gradient, at all early time points, than in the absence of the gradient. Proton-stimulated uptake of [14C]-guanidine at 30 sec (32.0 ± 1.24 pmol/mg protein) was significantly inhibited by a number of organic cations including 5 mM unlabeled guanidine (14.8 ± 1.84 pmol/mg protein) and 5 mM MIBA (9.14 ± 3.80 pmol/ mg protein), but not by 5 mM TEA (28.4 ± 5.67 pmol/mg protein). Guanidine, but not TEA, trans-stimulated [14C]-guanidine uptake. Conversely, TEA, but not guanidine, trans-stimulated [14C]-TEA uptake in the vesicles. The proton-dependent transport of guanidine was characterized by a Km of 3.52 ± 0.42 mM (SE) and a Vmax of 34.6 ± 8.64 pmol/mg protein/sec (SE). Conclusions. These results demonstrate that guanidine transport in human renal brush border membrane vesicles is stimulated by a proton gradient. Evidence was obtained suggesting that the transporter for guanidine is distinct from the previously described organic cation proton antiporter for TEA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012164203648
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Functional and Molecular Characteristics of Na+-dependent Nucleoside Transporters (1997)
    Springer
    Pharmaceutical research 14 (1997), S. 1524-1532 
    Details
    ISSN: 1573-904X
    Keywords: nucleoside transporters ; review ; nucleoside analogs ; expression systems ; adenosine ; intestinal absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nucleoside transporters play a critical role in the absorption, disposition, and targeting of therapeutically used nucleosides and nucleoside analogs. This review is focused on the Na+-dependent, concentrative nucleoside transporters which are found in a variety of cells including renal, intestinal and hepatic epithelia. Five major Na+-dependent nucleoside transporter subtypes have been characterized in isolated tissue preparations: Nl is purine selective; N2 is pyrimidine selective and N3−N5 exhibit variable selectivity for both purine and pyrimidine nucleosides. The recent cloning of Nl and N2 nucleoside transporters has provided the first information on the molecular function and structure of concentrative nucleoside transporters. In this manuscript we review the characteristics of the various subtypes of nucleoside transporters and the molecular structure, functional properties, and tissue distribution of the cloned Na+-dependent nucleoside transporters. In addition, the interactions of nucleosides and nucleoside analogs with the cloned transporters in mammalian and amphibian expression systems are presented. Mammalian expression systems may be particularly useful during drug development in screening potential compounds for improved bioavailability and tissue specific targeting. Finally, we present our view of future areas of study in the field of nucleoside transporters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012113931332
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Decreased Expression and Activity of P-GIycoprotein in Rat Liver During Acute Inflammation (1998)
    Springer
    Pharmaceutical research 15 (1998), S. 706-711 
    Details
    ISSN: 1573-904X
    Keywords: multidrug resistance ; P-glycoprotein ; inflammation ; acute phase response ; gene regulation ; drug disposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. Drug disposition is often altered in inflammatory disease. Although the influence of inflammation on hepatic drug metabolism and protein binding has been well studied, its impact on drug transport has largely been overlooked. The multidrug resistance (MDR) gene product, P-glycoprotein (P-gp) is involved in the active secretion of a large variety of drugs. Our goal was to ascertain the influence of acute inflammation (AI) on the expression and functional activity of P-gp. Methods. AI was induced in rats through turpentine or lipopolysaccharide (LPS) administration. Expression of P-gp in liver was detected at the level of protein on Western blots using the monoclonal antibody C-219 and at the level of mRNA using an RNase protection assay. P-gp mediated transport activity was assessed by measuring the verapamil-inhibitable efflux of rhodamine 123 (R123) in freshly isolated hepatocytes. Results. Turpentine-induced AI significantly decreased the hepatic protein expression of P-gp isoforms by 50−70% and caused a significant 45−65% reduction in the P-gp mediated efflux of R123. Diminished mRNA levels of all three MDR isoforms were seen. LPS-induced AI similarly resulted in significantly reduced levels and activity of P-gp in liver. Although differences in the constitutive levels of P-gp were seen between male and female rats, the influence of AI on P-gp expression and activity was not gender specific. Conclusions. Experimentally-induced inflammation decreases the in vivo expression and activity of P-gp in liver. This is the first evidence that expression of P-gp is modulated in response to experimentally-induced inflammation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011962818051
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...