PREOPTIC RECESS LESIONS REDUCE RIGHT ATRIAL PRESSURE RESPONSES TO VOLUME EXPANSION

Authors
Citation
Sl. Bealer, PREOPTIC RECESS LESIONS REDUCE RIGHT ATRIAL PRESSURE RESPONSES TO VOLUME EXPANSION, Journal of the autonomic nervous system, 60(3), 1996, pp. 175-181
Citations number
26
Categorie Soggetti
Neurosciences
ISSN journal
01651838
Volume
60
Issue
3
Year of publication
1996
Pages
175 - 181
Database
ISI
SICI code
0165-1838(1996)60:3<175:PRLRRA>2.0.ZU;2-F
Abstract
Ablation of the periventricular tissue surrounding the anteroventral p ortion of the third cerebral ventricle (AV3V-X) abolishes natriuresis and diuresis during volume expansion. Although deficits in several eff erent mechanisms have been identified, effects of AV3V-X on afferent i nput to the volume reflex have not been investigated. Therefore, these experiments measured right atrial pressure (RAP) in conscious AV3V-X and control-operated (CONT) rats before, during, and following acute ( 60 s) or continuous (60 min) infusion of isotonic saline, or vascular volume expansion with whole blood (15 min). Changes in RAP were signif icantly smaller in AV3V-X rats than CONT animals during acute isotonic saline infusion and during whole-blood expansion. Treatment with hexa methonium abolished the difference in RAP during acute volume infusion . However, then was no significant difference in RAP between groups du ring continuous isotonic saline expansion. These data suggest that AV3 V-X reduces afferent input from cardiopulmonary stretch receptors duri ng acute volume expansion, which may contribute to diminished natriure sis and diuresis observed in these animals.