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

Interactions between sodium chloride intake and AT1-receptor blockade on renal endothelin system gene expression in rats

Einflüsse der NaCl-Aufnahme und AT1-Rezeptor-Blockade auf die renale Genexpression von Komponenten des Endothelinsystems

Meeting Abstract (Hypertonie 2003)

Suche in Medline nach

  • presenting/speaker R. Grimm - Universität Greifswald (Karlsburg, D)
  • F. Klinger - Universität Greifswald (Karlsburg, D)
  • R. Rettig - Universität Greifswald (Karlsburg, D)
  • O. Grisk - Universität Greifswald (Karlsburg, D)

Hypertonie 2003. 27. Wissenschaftlicher Kongress der Deutschen Hochdruckliga. Bonn, 26.-29.11.2003. Düsseldorf, Köln: German Medical Science; 2004. Doc03hochV15

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/hoch2003/03hoch015.shtml

Veröffentlicht: 11. November 2004

© 2004 Grimm 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

The renal endothelin system participates in the regulation of body fluid and electrolyte homeostasis. We investigated if changes in NaCl intake affect renal cortical and medullary mRNA expression of ETA, ETB-receptors, and pre-pro-ET-1 by real time RT-PCR. Further, the responsiveness of expression levels to AT1-receptor blockade was tested. Male Sprague-Dawley rats were randomised to 6 groups (n = 8) receiving 1.8, 0.6 or 0.12 % NaCl diet with or without oral administration of losartan (30 mg/kg*d). Without losartan MAP was 110 mmHg in all diet groups. Losartan reduced MAP by 20 mmHg irrespective of NaCl intake (p < 0.001). Cortical ETA expression was not significantly altered by NaCl intake. Losartan reduced cortical ETA expression by 30 % in the 0.12 % NaCl diet but not in the other diet groups (p < 0.05). Medullary ETA expression was elevated by 30 % under 0.12% NaCl compared to 1.8 and 0.6 % NaCl (p < 0.05). This effect was abolished by losartan. ETB expression was not significantly affected by any intervention. Cortical pre-pro-ET1 expression showed a slight inverse relation to NaCl intake. Losartan administration increased cortical pre-pro-ET-1 expression on 1.8 and 0.6 % NaCl by 30-40% (p < 0.05) but was without effect on 0.12% NaCl. Medullary pre-pro-ET-1 expression was not affected by any intervention. Reduction in NaCl intake by factor 15 increases the dependence of cortical and medullary ETA but not ETB recpetor mRNA expression on AT1-receptor stimulation. Conversely, cortical expression of pre-pro-ET1 does not depend on AT1-receptor stimulation on low NaCl intake but can be increased by AT1 blockade with elevated NaCl intake.