EurekaMag.com logo
+ Site Statistics
References:
47,893,527
Abstracts:
28,296,643
+ 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

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

Itoh H.; Bunag R.D., 1992: Catecholaminergic nucleus tractus solitarius lesions in anesthetized rats alter baroreflexes differently with age. To explore whether catecholaminergic lesions produced chemically in the nucleus tractus solitarius (NTS) would alter the baroreflex impairment that normally occurs with age, we compared baroreflex responses in 3- and 14-month-old rats given bilate...

Guimaraes, P.S.; Huber, D.A.; Campagnole-Santos, M.J.; Schreihofer, A.M., 2014: Development of attenuated baroreflexes in obese Zucker rats coincides with impaired activation of nucleus tractus solitarius. Adult obese Zucker rats (OZR; >12 wk) develop elevated sympathetic nerve activity (SNA) and mean arterial pressure (MAP) with impaired baroreflexes compared with adult lean Zucker rats (LZR) and juvenile OZR (6-7 wk). In adult OZR, baroreceptor...

Dean, C.; Hermes, C.A.; Robinson, J.; Seagard, J.L., 1998: Modulation of arterial baroreflexes by antisense oligodeoxynucleotides to NMDAR1 receptors in the nucleus tractus solitarius. An antisense oligodeoxynucleotide which specifically blocked the production of the glutamate receptor subtype NMDAR1 was administered to the nucleus tractus soIitarius (NTS) in order to examine the role of this receptor in baroreflex control of he...

Dean, C.; Hermes, C.A.; Robinson, J.; Seagard, J.L., 1999: Modulation of arterial baroreflexes by antisense oligodeoxynucleotides to NMDAR1 receptors in the nucleus tractus solitarius. An antisense oligodeoxynucleotide which specifically blocked the production of the glutamate receptor subtype NMDAR1 was administered to the nucleus tractus solitarius (NTS) in order to examine the role of this receptor in baroreflex control of he...

Casto, R.; Phillips, M.I., 1984: Mechanism of pressor effects by angiotensin in the nucleus tractus solitarius of rats. We recently reported that microinjection of angiotensin II (ANG II) into the nucleus tractus solitarius (NTS) results in an increase in mean arterial pressure (MAP) in urethan-anesthetized rats in a dose range of 50-500 ng. To investigate the mech...

Andrews, C.O.; Crim, J.W.; Hartle, D.K., 1993: Angiotensin II binding in area postrema and nucleus tractus solitarius of SHR and WKY rats. The distribution of angiotensin II (AII) binding sites in the area postrema (AP) and adjacent nucleus tractus solitarius (NTS) was compared in spontaneously hypertensive (SHR) rats and normotensive Wistar-Kyoto (WKY) rats. 125I[Saralasin-1-Isoleuc...

Andrews, C.O.; Crim, J.W.; Hartle, D.K., 1993: Angiotensin II binding in area postrema and nucleus tractus solitarius of SHR and WKY rats. The distribution of angiotensin II (AII) binding sites in the area postrema (AP) and adjacent nucleus tractus solitarius (NTS) was compared in spontaneously hypertensive (SHR) rats and normotensive Wistar-Kyoto (WKY) rats. 125I[Saralasin-1-Isoleuc...

Wang, X.; Abdel-Rahman, A.A., 2004: An association between ethanol-evoked enhancement of c-jun gene expression in the nucleus tractus solitarius and the attenuation of baroreflexes. Background: An increased expression of Fos, the protein product of the immediate early gene c-fos, in the nucleus tractus solitarius (NTS) is associated with dysfunction in baroreceptor reflex control of heart rate. Our previous studies demonstrat...

Casto, R.; Phillips, M.I., 1985: Neuropeptide action in nucleus tractus solitarius: angiotensin specificity and hypertensive rats. We have reported that microinjection of angiotensin II (ANG II) into the nucleus tractus solitarius of urethan-anesthetized normotensive rats produces an increase in mean arterial pressure (MAP) over the dose range 50-500 pmol. The effect in spont...