Parasympathetic response to acute stress is attenuated in young Zucker obese rats

Autonomic Neuroscience : Basic & Clinical
Yasser M El-WazirDavid C Randall

Abstract

We compared arterial blood pressure (BP) and heart rate (HR) control in 9- to 11-week old obese Zucker rats (n=10; weight=452+/-45 g, average+/-SD) to age-matched, lean Zucker animals (n=13; weight=280+/-46 g). BP was measured by indwelling catheter. Baseline pressure was 113.1+/-7.0 mm Hg in the lean vs. 111.7+/-5.6 in the obese rats (NS). Baseline HR was 413+/-43 in the lean vs. 422+/-22 bpm in the obese animals (NS). Rats were classically conditioned by following a 15-second tone (CS+) with a 0.5-second tail shock. There were no between-group differences in the BP response to CS+. Conversely, heart rate (HR) decreased significantly (p<0.05) more during the last 10 s of the tone in the lean group (-46.0+/-21.5 bpm) vs. the obese (-17.8+/-21.7 bpm). This bradycardia was blocked by atropine. Finally, the change in HR divided by the change in arterial BP (DeltaHR/DeltaBP) following an intravenous bolus of phenylephrine (PE; 5 microg/kg) and following sodium nitroprusside (NP; 5 microg/kg) was determined. The DeltaHR/DeltaBP following PE was smaller in the obese (n=6; -1.36+/-0.60) vs. lean (n=5; -2.80+/-0.92); there was no difference in the response following NP. These data indicate that the BP response to a behavioral challenge...Continue Reading

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Apr 30, 2005·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Yasser M El-WazirDavid C Randall
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Citations

Dec 19, 2009·Autonomic Neuroscience : Basic & Clinical·Winston Y LiDavid C Randall
Jan 16, 2013·Autonomic Neuroscience : Basic & Clinical·Richard E HoytDavid C Randall
Jun 10, 2016·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Domitila A Huber, Ann M Schreihofer
Nov 5, 2010·Anesthesia and Analgesia·Alexander ZlotnikVivian I Teichberg
Feb 28, 2014·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Priscila S GuimaraesAnn M Schreihofer

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