gms | German Medical Science

28. Wissenschaftlicher Kongress der Deutschen Hochdruckliga

24. bis 27.11.2004, Hannover

Influence of Short-term versus Prolonged Cardiopulmonary Receptor Stimulation on Renal and Adrenal Sympathetic Nerve Activity in Rats

Kurzfristige und prolongierte Stimulation kardiopulmonaler Rezeptoren: Einfluß auf renalen und adrenalen Sympathikus

Meeting Abstract (Hypertonie 2004)

Suche in Medline nach

  • T. Ditting - Dept. Nephrology J. W. Goethe-University (Frankfurt, D)
  • K.F. Hilgers - Dept. Nephrology, Friedrich-Alexander-University Erlangen, D)
  • K. Amann - Dept. Pathology, Friedrich-Alexander-University Erlangen, D)
  • R. Veelken - Dept. Pathology, Friedrich-Alexander-University Erlangen, D)

Hypertonie 2004. 28. Wissenschaftlicher Kongress der Deutschen Hochdruckliga. Hannover, 24.-27.11.2004. Düsseldorf, Köln: German Medical Science; 2005. Doc04hochP37

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/hoch2004/04hoch037.shtml

Veröffentlicht: 10. August 2005

© 2005 Ditting 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

Renal and preganglionic adrenal sympathetic nerve activity (RSNA, ASNA) are known to be regulated differentially. We investigated different modes of cardiopulmonary receptor stimulation (mechanical/chemical) to distinguish between 1) short-term and prolonged stimulus effects on sympathetic nerve activity (SNA) as well as 2) stimulus specific effects.

In rats mean arterial blood pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP), renal and adrenal sympathetic nerve activity (RSNA, ASNA) were measured. Experiments were repeated with bilateral cervical vagotomy (Vx). Cardiopulmonary receptors were stimulated in different ways: Short-term: LVEDP changes (±4, ±6, ±8 mmHg) by aortic or caval vein obstruction, respectively; 5HT3-receptor stimulation by phenylbiguanide (PBG-boli iv); Prolonged (15 minutes): volume expansion to increase LVEDP (0.9% NaCl, 5% body weight); hemorrhage to decrease LVEDP by 50 mmHg; PBG infusion (32µg/min).

Short-term increases and decreases of LVEDP uniformly decreased SNA (RSNA -52±12%; ASNA -37±13%, n=8). PBG-bolus decreased RSNA (-54±12%) but increased ASNA (+40±13%). All reflex responses were abolished by Vx. Volume expansion decreased RSNA (-55±7%) but did not affect ASNA. PBG-infusion lead to sustained decrease in RSNA (-60±6%) but lead to non-sustained (2min) increase in ASNA (+120±15%), resembling short-term stimulus response. Again all responses were abolished by Vx. Hemorrhage decreased RSNA (-39±9%) but increased ASNA (+42±9%). RSNA response was abolished by Vx. but not ASNA.

Short-term mechanical stimulation of cardiopulmonary receptors uniformly decreased RSNA and ASNA whereas short-term chemical stimulation induced opposed responses in respective SNA. However, the major finding was that ASNA in contrast to RSNA ASNA was unaffected by prolonged stimulation of cardiopulmonary receptors independent of the stimulus mode. This points to differential central processing of afferent input.