Comparison of atrial natriuretic peptide binding and sensitivity in
brains from hypertensive and normotensive rats.
Grove, Kevin L., Jason Gon[cedilla]calves, Sylvie Picard, Gaetan
Thibault, and Christian F. Deschepper.
Laboratories of Neurobiology and Vasoactive Peptides and Cell
Biology of Hypertension, MRC Multidisciplinary Research Group on
Hypertension, Institut de Recherches Clinique de Montr[acute]eal
(IRCM) and Universit[acute]e de Montr[acute]eal, Montr[acute]eal
(Qu[acute]ebec) Canada H2W 1R7
APStracts 3:0402R, 1996.
We compared the abundance and sensitivity of atrial natriuretic
peptides (ANP) receptors in the brains of spontaneously hypertensive
(SHR) and Wistar-Kyoto (WKY) rats, and examined the effect of blood
pressure on the abundance brain ANP receptors in several other
experimental rat models. Brain slices from spontaneously hypertensive
rats (SHR) generated more cyclic guanosine monophosphate (cGMP) in
response to ANP than brain slices from Wistar-Kyoto (WKY) rats. No
differences were found in brain particulate guanylate cyclase
activity in both strains of rats. In rat brain homogenates, we
observed that ANP bound in a specific and saturable fashion to
samples from WKY rats, but not in samples from SHR. In vitro receptor
autoradiography revealed that ANP binding was reduced in the
subfornical organ, the choroid plexus and the paraventricular nucleus
of SHR as compared to WKY rat brains. Correction of hypertension in
SHR or induction of hypertension in other strains did not affect ANP
binding in any of these brain regions. Altogether, our data suggest
that the increased sensitivity of SHR brains to the action of ANP may
be a consequence of factors other than the abundance of receptors,
and that it is not secondary to the elevation of blood pressure.
Received 17 July 1996; accepted in final form 15 November 1996.
APS Manuscript Number R410-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996