EurekaMag.com logo
+ Site Statistics
References:
52,725,316
Abstracts:
28,411,598
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Angiotensin II attenuates baroreflexes at nucleus tractus solitarius of rats






American Journal of Physiology 250(2 Pt 2): R193-R198

Angiotensin II attenuates baroreflexes at nucleus tractus solitarius of rats

Microinjection of angiotensin II (ANG II) into the nucleus tractus solitarius (NTS) has been shown to produce a dose-dependent increase in blood pressure and heart rate. We have tested the effect of subpressor infusions of ANG II (10 ng .cntdot. kg-1 .cntdot. min-1) in the NTS on reflex bradycardia after intravenous administration of the vasoconstrictor phenylephrine (1-12 .mu.g) in normotensive urethan-anesthetized rats. ANG II within the brain is thought to contribute to the decreased baroreflex sensitivity in spontaneously hypertensive rats (SHR). The sensitivity of the baroreflex was significantly decreased by the infusion of ANG II (1.01 .+-. 0.08) compared with control (2.41 .+-. 0.051) in the normotensive animals. Baroreflex sensitivity was significantly decreased in SHR (0.40 .+-. 0.21) compared with normotensive animals. We conclude that ANG II within the NTS can inhibit the function of baroreceptor reflexes in normotensive animals, suggesting that the endogenous peptide may perform an inhibitory role in the baroreflex arc, and this is further evidence that central ANG II is involved in blood pressure of SHR.


Accession: 004750415

PMID: 3946636



Related references

Adenosine A-1 receptor antisense oligodeoxynucleotide microinjected into the nucleus tractus solitarius attenuates baroreflexes in conscious rats. Circulation 90(4 PART 2): I474, 1994

Catecholaminergic nucleus tractus solitarius lesions in anesthetized rats alter baroreflexes differently with age. Mechanisms of Ageing & Development 64(1-2): 69-84, 1992

Development of attenuated baroreflexes in obese Zucker rats coincides with impaired activation of nucleus tractus solitarius. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 306(9): R681-R692, 2014

Modulation of arterial baroreflexes by antisense oligodeoxynucleotides to NMDAR1 receptors in the nucleus tractus solitarius. Journal of the Autonomic Nervous System 74(2-3): 109-115, Dec 11, 1998

Modulation of arterial baroreflexes by antisense oligodeoxynucleotides to NMDAR1 receptors in the nucleus tractus solitarius. Journal of the Autonomic Nervous System 74(2-3): 109-115, 1999

Mechanism of pressor effects by angiotensin in the nucleus tractus solitarius of rats. American Journal of Physiology 247(3 Pt 2): R575-R581, 1984

Angiotensin II binding in area postrema and nucleus tractus solitarius of SHR and WKY rats. Brain Research Bulletin. 32(4): 419-424, 1993

An association between ethanol-evoked enhancement of c-jun gene expression in the nucleus tractus solitarius and the attenuation of baroreflexes. Alcoholism, Clinical and Experimental Research 28(8): 1264-1272, 2004

Neuropeptide action in nucleus tractus solitarius: angiotensin specificity and hypertensive rats. American Journal of Physiology 249(3 Pt 2): R341-R347, 1985

Blockade of non n methyl d aspartic acid nmda receptors in the nucleus of the tractus solitarius nts eliminates aortic baroreflexes. Society for Neuroscience Abstracts 15(2): 1178, 1989