Affordable Access

Central nervous system cardiovascular actions of CRF in sinoaortic-denervated rats.

Authors
  • Overton, J M
  • Davis-Gorman, G
  • Fisher, L A
Type
Published Article
Journal
The American journal of physiology
Publication Date
Mar 01, 1990
Volume
258
Issue
3 Pt 2
Identifiers
PMID: 2316708
Source
Medline
License
Unknown

Abstract

Studies were performed in unrestrained conscious Sprague-Dawley rats to examine the central nervous system (CNS) mechanism by which corticotropin-releasing factor (CRF) produces simultaneous elevations of arterial pressure and heart rate. To test the hypothesis that CRF inhibits ongoing impulse transmission through and/or transmitter release from the CNS terminations of baroreceptor afferents, the cardiovascular effects of intracerebroventricular administration of CRF were compared in rats subjected to prior sham surgery (Sham) or sinoaortic denervation (SAD). Resting levels of arterial pressure and heart rate were elevated after SAD. In addition, SAD resulted in greater chronotropic sympathetic tone and reduced chronotropic parasympathetic tone as assessed by intravenous injections of atropine methyl nitrate and DL-propranolol. Intracerebroventricular administration of CRF in both surgical groups elicited significant increases in arterial pressure and heart rate, although a tendency for reduced tachycardic responses after SAD was apparent. Pretreatment with atropine or propranolol revealed that both the parasympathetic and sympathetic nervous systems contribute to CRF-induced heart rate responses in both surgical groups. These results suggest that ongoing baroreceptor afferent transmission is not requisite for the expression of CRF-induced cardiovascular changes. Thus it is unlikely that CRF elevates arterial pressure and heart rate through an exclusive action at the CNS terminations of baroreceptor sensory fibers.

Report this publication

Statistics

Seen <100 times