Sinoaortic denervation prevents postexercise reductions in arterial pressure and cardiac sympathetic tonus.

Title

Sinoaortic denervation prevents postexercise reductions in arterial pressure and cardiac sympathetic tonus.

Creator

Chandler M P; DiCarlo S E

Publisher

The American journal of physiology

Date

1997
1997-12

Description

Arterial pressure, cardiac sympathetic tonus (ST), and heart rate (HR) are reduced after a single bout of dynamic exercise in spontaneously hypertensive rats (SHR). To test if the arterial baroreflex is required for these postexercise responses, intact (n = 9) and sinoaortic-denervated (SAD) rats (n = 5) were chronically instrumented with an arterial catheter for the measurement of arterial pressure and HR and for the infusion of cardiac autonomic antagonists. Five days after instrumentation, cardiac ST and parasympathetic tonus (PT) were determined under two experimental conditions (no exercise and postexercise). SAD rats did not alter no-exercise cardiac ST (intact 47 +/- 3 vs. SAD 50 +/- 3 beats/min); however, no-exercise PT was reduced (intact -24 +/- 2 vs. SAD -4 +/- 4 beats/min, P \textless 0.05). Acute exercise reduced arterial pressure (postexertional hypotension, -20 +/- 3 mmHg, P \textless 0.05), cardiac ST (no exercise 47 +/- 3 vs. postexercise 24 +/- 3 beats/min, P \textless 0.05), and PT (no exercise -24 +/- 2 vs. postexercise -11 +/- 2 beats/min, P \textless 0.05) in intact SHR. In contrast, SAD prevented postexercise reductions in arterial pressure and cardiac ST (no exercise 50 +/- 3 vs. postexercise 59 +/- 7 beats/min). Furthermore, SAD had no effect on postexercise PT (no exercise -4 +/- 4 vs. postexercise -7 +/- 4 beats/min). These results demonstrate that the arterial baroreflex is required for the reduction in arterial pressure and cardiac ST that occurs in SHR after a single bout of dynamic exercise.

Subject

*Muscle Denervation; Animals; Autonomic Nervous System/physiology/physiopathology; Blood Pressure/*physiology; Heart Rate/*physiology; Heart/innervation/*physiology/physiopathology; Hypertension/*physiopathology; Inbred SHR; Male; Muscle Tonus; Physical Exertion/*physiology; Rats; Sinoatrial Node/*innervation; Sympathetic Nervous System/*physiology/physiopathology

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

H2738–2745

Issue

6

Volume

273

Citation

Chandler M P; DiCarlo S E, “Sinoaortic denervation prevents postexercise reductions in arterial pressure and cardiac sympathetic tonus.,” NEOMED Bibliography Database, accessed October 27, 2021, https://neomed.omeka.net/items/show/4622.

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