| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
AJP - Regulatory, Integrative and Comparative Physiology, Vol 264, Issue 2 388-R395, Copyright © 1993 by American Physiological Society
ARTICLES |
H. Muratani, C. M. Ferrario and D. B. Averill
Department of Brain and Vascular Research, Cleveland Clinic Foundation, Ohio 44195.
We investigated whether angiotensin II (ANG II), endogenous to the ventrolateral medulla (VLM), contributes to cardiovascular regulation in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. The action of ANG II endogenous to the VLM was examined by microinjection of 100 pmol of [Sar1,Thr8]ANG II into either the rostral (R) or caudal (C) VLM. This ANG II antagonist caused depressor and bradycardic responses in the RVLM and pressor and tachycardic responses in the CVLM. The magnitude of the blood pressure responses was significantly greater (P < 0.01 in RVLM and P < 0.05 in CVLM) in SHRs (-27 +/- 3 mmHg in RVLM and 29 +/- 4 mmHg in CVLM) than in WKY rats (-17 +/- 1 and 17 +/- 2 mmHg, respectively). Suppression of tonic activity of RVLM neurons by bilateral injection of muscimol in the RVLM showed that the pressor response produced by ANG II antagonist injection in the CVLM required the integrity of rostral pressor neurons. The present data suggest that ANG II endogenous to RVLM and CVLM acts as a tonic excitatory agent on vasomotor neurons of the VLM. The contribution of ANG II in the RVLM and CVLM to the prevailing level of blood pressure was significantly (P < 0.01) larger in SHRs vs. WKY rats when the effect of ANG II blockade was measured as the change in blood pressure. Blockade of gamma-aminobutyric acid (GABA)A receptors in the RVLM showed that inhibitory GABAergic input to the RVLM was not diminished in this strain.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
|
|
 |
|
  K. D. Rowe, J. A. Schwartz, L. L. Lomax, and M. M. Knuepfer Central angiotensin II receptors mediate hemodynamic response variability to stressors Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2006; 291(3): R719 - R727. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Alzamora, R. A. S. Santos, and M. J. Campagnole-Santos Baroreflex modulation by angiotensins at the rat rostral and caudal ventrolateral medulla Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2006; 290(4): R1027 - R1034. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Alzamora, R. A. S. Santos, and M. J. Campagnole-Santos Hypotensive effect of ANG II and ANG-(1-7) at the caudal ventrolateral medulla involves different mechanisms Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2002; 283(5): R1187 - R1195. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Baltatu, M. A. P. Fontes, M. J. Campagnole-Santos, S. Caligiorni, D. Ganten, R. A. S. Santos, and M. Bader Alterations of the renin-angiotensin system at the RVLM of transgenic rats with low brain angiotensinogen Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2001; 280(2): R428 - R433. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Ito and A. F. Sved Pharmacological profile of depressor response elicited by sarthran in rat ventrolateral medulla Am J Physiol Heart Circ Physiol, December 1, 2000; 279(6): H2961 - H2966. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. D. Potts, A. M. Allen, J. Horiuchi, and R. A. L. Dampney Does angiotensin II have a significant tonic action on cardiovascular neurons in the rostral and caudal VLM? Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2000; 279(4): R1392 - R1402. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Ito, K. Komatsu, K. Tsukamoto, and A. F. Sved Excitatory Amino Acids in the Rostral Ventrolateral Medulla Support Blood Pressure in Spontaneously Hypertensive Rats Hypertension, January 1, 2000; 35(1): 413 - 417. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. T. Bergamaschi, R. R. Campos, and O. U. Lopes Rostral Ventrolateral Medulla : A Source of Sympathetic Activation in Rats Subjected to Long-Term Treatment With L-NAME Hypertension, October 1, 1999; 34(4): 744 - 747. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. A. Gaudet, S. J. Godwin, and G. A. Head Role of central catecholaminergic pathways in the actions of endogenous ANG II on sympathetic reflexes Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1998; 275(4): R1174 - R1184. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Sesoko, H. Muratani, M. Yamazato, H. Teruya, S. Takishita, and K. Fukiyama Contribution of alpha 2-adrenoceptors in caudal ventrolateral medulla to cardiovascular regulation in rat Am J Physiol Regulatory Integrative Comp Physiol, April 1, 1998; 274(4): R1119 - R1124. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-W. Li and P. G. Guyenet Angiotensin II Decreases a Resting K+ Conductance in Rat Bulbospinal Neurons of the C1 Area Circ. Res., February 1, 1996; 78(2): 274 - 282. [Abstract] [Full Text]
|
|
|
|
|
|
Y. Hirooka, G. A. Head, P. D. Potts, S. J. Godwin, R. D. Bendle, and R. A.L. Dampney Medullary Neurons Activated by Angiotensin II in the Conscious Rabbit Hypertension, February 1, 1996; 27(2): 287 - 296. [Abstract] [Full Text]
|
|
|
|
 |
|
 L. Hu, D.-N. Zhu, Z. Yu, J. Q. Wang, Z.-J. Sun, and T. Yao Expression of angiotensin II type 1 (AT1) receptor in the rostral ventrolateral medulla in rats J Appl Physiol, May 1, 2002; 92(5): 2153 - 2161. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
