gms | German Medical Science

27. Wissenschaftlicher Kongress der Deutschen Hochdruckliga

Deutsche Liga zur Bekämpfung des hohen Blutdrucks – Deutsche Hypertonie Gesellschaft e. V.

26. bis 29.11.2003, Bonn

Ramiprilat inhibits reactive oxygene species production by inhibiting NADPH oxidase

Ramiprilat vermindert die NADPH oxidase vermittelte Sauerstoffradikalprodukation

Meeting Abstract (Hypertonie 2003)

  • presenting/speaker M. Tölle - Charite - Universitätsmedizin Berlin (Berlin, D)
  • G. Giebing - Charite - Universitätsmedizin Berlin (Berlin, D)
  • S. Schmidt - Charite - Universitätsmedizin Berlin (Berlin, D)
  • M. Tepel - Charite - Universitätsmedizin Berlin (Berlin, D)
  • W. Zidek - Charite - Universitätsmedizin Berlin (Berlin, D)
  • M. van der Giet - Charite - Universitätsmedizin Berlin (Berlin, D)

Hypertonie 2003. 27. Wissenschaftlicher Kongress der Deutschen Hochdruckliga. Bonn, 26.-29.11.2003. Düsseldorf, Köln: German Medical Science; 2004. Doc03hochV14

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/hoch2003/03hoch014.shtml

Veröffentlicht: 11. November 2004

© 2004 Tölle et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

In the last years there is increasing evidence that angiotensin-converting enzyme inhibitors (ACEI) may influence production of reactive oxygene species. Until now it is not clear whether ACEI can directly influence generation of reactive species (ROS) or other mechanisms are involved. In the present study we investigated whether the ACEI ramiprilat directly interacts with the vascular NADPH-oxidase.

Generation of intracellular ROS in vascular smooth muscle cells (VSMC) were determined with a fluorescence spectrophotometer using dichlorofluorescein diacetate (DCFDA). Generation of ROS in VSMCs was directly demonstrated using dihydroethidium (DHE) in a confocal laser scanning microscope. Superoxide radical production in VSMCs was measured with chemiluminescence using lucigenin. NADPH oxidase activity in membranes of VSMCs was determined photometrically. The effects of ramiprilat on NADPH oxidase expression in VSMCs was monitored using realtime PCR of p22phox expression.

Ramiprilat (100 nmol/L) and the NADPH-oxidase apocynin (10 µmol/L) directly reduced thrombin (3U/ml) induced ROS formation in VSMCs using DHE. Using DCFDA it could be demonstrated that ramiprilat reduced NADPH oxidase in a dose-dependent way. Significant inhibition of NAPDH-oxidase by ramiprilat was observed at concentrations of 1 nmol/L ramiprilat. NADPH oxidase acitivity in cellmembranes of VSMCs was significantly blocked by ramiprilat (10 nmoL/L; 43±3% of control) and apocynin (10 µmol/L; 2±1% of control). Stimulation of VSMCs fr 16 hours with thrombin (3U/ml) did not affect expression of p22phox as measured by realtime PCR. In the presence of apocynin (10 µmol/L) or ramiprilat (10 nmol/L) no change of p22phox expression could be observed.

In the present study we can demonstrate that the ACEI ramiprilat can directly affect vascular NADPH oxidase. The effect ist nod dependent of the presence of a thiol-group and occurs with therapeutically relevant concentrations of ramiprilat.