Baroreflex control of heart rate and cardiac hypertrophy in angiotensin II-induced hypertension in rabbits

Hypertension
Simon C MalpasGeoffrey A Head

Abstract

The cardiac hypertrophy observed in hypertension is thought to be responsible for the accompanying deficiency in the baroreflex control of heart rate. In this study, we assessed the baroreflex relationship between heart rate and arterial pressure on a group of seven rabbits during a normotensive period, during the early phase of angiotensin II (Ang II)-induced hypertension II week) (50 ng/kg per minute i.v. via osmotic minipumps), after 7 weeks of continuous hypertension, then 2 days after Ang II was stopped, and finally 7 days after Ang II. Left ventricles were weighed for measurement of left ventricular weight-body weight ratio. One week of intravenous Ang II infusion produced hypertension (mean arterial pressure from 80 +/- 2 up to 115 +/- 8 mm Hg), with significantly increased heart rate and hematocrit. The heart rate-arterial pressure baroreflex curve was shifted to the right, with a significant 45% reduction in the gain of the reflex (-6.4 +/- 1.5 to -3.5 +/- 0.2 beats per minute/mm Hg). After 7 weeks of Ang II, arterial pressure was still elevated (112 +/- 4 mm Hg) and the gain of the baroreflex curve still somewhat attenuated, although it was no longer markedly different from normotensive levels (gain, -5.09 +/- 0.95, 2...Continue Reading

References

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Citations

Sep 21, 2000·Pathophysiology : the Official Journal of the International Society for Pathophysiology·S C Tyagi
Mar 21, 2002·Clinical and Experimental Pharmacology & Physiology·G A Head, S L Burke
Sep 5, 2002·Clinical and Experimental Pharmacology & Physiology·Rohit RamchandraSimon C Malpas
Jul 15, 2004·Nephrology, Dialysis, Transplantation : Official Publication of the European Dialysis and Transplant Association - European Renal Association·Masato NishimuraToshihiko Ono
Aug 7, 2001·Journal of Cardiovascular Pharmacology·Z Z ShanD F Su
Apr 28, 2005·Clinical and Experimental Pharmacology & Physiology·Sarah-Jane GuildSimon C Malpas
Aug 30, 2008·Epilepsia·Cameron S MetcalfSteven L Bealer
Feb 25, 2014·Autonomic Neuroscience : Basic & Clinical·Elizabeth B Oliveira-SalesJulian F R Paton
Aug 18, 2006·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Simon C MalpasCarolyn J Barrett
Oct 12, 2002·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Sarah-Jane GuildRoger G Evans
Sep 12, 2019·Clinical and Experimental Pharmacology & Physiology·Emmanuel Veríssimo de AraújoJosé Luiz de Brito Alves
Sep 5, 1998·The American Journal of Physiology·P LantelmeM Ducher
Oct 23, 2012·American Journal of Physiology. Heart and Circulatory Physiology·Satoshi KobaTatsuo Watanabe
Feb 9, 2000·American Journal of Physiology. Heart and Circulatory Physiology·E GaudetG A Head
Sep 17, 2005·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Radu IliescuJane F Reckelhoff

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