|
|
||||||||
Departments of 1 Veterinary PathoBiology, 2 Animal Science, and 3 Physiology, University of Minnesota, St. Paul, Minnesota 55108
We reported that the
AT1 receptor antagonist losartan
decreases arterial pressure in sodium-replete rats and that this
response is attenuated in area postrema-lesioned (APx) rats (J. P. Collister, B. J. Hornfeldt, and J. W. Osborn.
Hypertension 27: 598-606, 1996). In that study, food intake for the 3-wk period after sham lesion was
restricted to that observed in APx rats. Food-restricted sham rats had
lower arterial pressures and attenuated responses to losartan compared
with control rats fed ad libitum. The present study examined whether
these differences persisted months, rather than weeks after APx or sham
lesions. Losartan was administered for 10 days to APx and two groups of
sham rats 3 mo after APx or sham surgery. The first sham group was food
restricted (SFR) for 3 wk after surgery, whereas the second sham group
was allowed ad libitum (SAL) access to food. By
day 8 of losartan administration, both sham groups demonstrated a marked
hypotension (SFR:
38 ± 4; SAL:
33 ± 4 mmHg). This
response was attenuated (P < 0.05) on the same day in APx rats (
17 ± 3 mmHg). This trend
continued throughout days
9 and
10. Because both sham groups responded
similarly to losartan (yet significantly different from APx rats),
these results demonstrate that transient decreases in food intake do not affect the response to losartan if rats are allowed an adequate recovery period. We conclude that the area postrema mediates part of
the long-term hypotensive effects of
AT1 receptor blockade in the
conscious rat.
circumventricular organ; angiotensin II; food restriction; chronic arterial pressure regulation
This article has been cited by other articles:
![]() |
D. B. Nahey and J. P. Collister ANG II-induced hypertension and the role of the area postrema during normal and increased dietary salt Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H694 - H700. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W. Osborn, F. Jacob, and P. Guzman A neural set point for the long-term control of arterial pressure: beyond the arterial baroreceptor reflex Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2005; 288(4): R846 - R855. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. D. Hendel and J. P. Collister Contribution of the subfornical organ to angiotensin II-induced hypertension Am J Physiol Heart Circ Physiol, February 1, 2005; 288(2): H680 - H685. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W. Osborn, P. Ariza-Nieto, J. P. Collister, S. Soucheray, B. Zimmerman, and S. Katz Responsiveness vs. basal activity of plasma ANG II as a determinant of arterial pressure salt sensitivity Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H2142 - H2149. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Jacob, P. Ariza, and J. W. Osborn Renal denervation chronically lowers arterial pressure independent of dietary sodium intake in normal rats Am J Physiol Heart Circ Physiol, June 1, 2003; 284(6): H2302 - H2310. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Katz, J. A. Opsahl, S. E. Wernsing, L. M. Forbis, J. Smith, and L. J. Heller Myocardial renin is neither necessary nor sufficient to initiate or maintain ventricular hypertrophy Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2000; 278(3): R578 - R586. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.-L. Liu, H. Murakami, M. Sanderford, V. S. Bishop, and I. H. Zucker ANG II and baroreflex function in rabbits with CHF and lesions of the area postrema Am J Physiol Heart Circ Physiol, July 1, 1999; 277(1): H342 - H350. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. P. Collister and J. W. Osborn The area postrema does not modulate the long-term salt sensitivity of arterial pressure Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1998; 275(4): R1209 - R1217. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |