Journal article
Frequency response characteristic of sympathetic-mediated vasomotor waves in conscious rats
American journal of physiology. Heart and circulatory physiology, Vol.271(4), pp.H1416-H1422
10/01/1996
DOI: 10.1152/ajpheart.1996.271.4.H1416
PMID: 8897935
Abstract
Power spectrum analysis of arterial blood pressure (BP) and heart rate (HR) has been used to investigate autonomic nervous system activity. Sympathetic-mediated vasomotor tone has been attributed to the BP power at frequencies between 0.05 and 0.15 Hz in humans and dogs and between 0.2 and 0.8 Hz in rats. In contrast, it has been suggested that the sympathetic nervous system is too sluggish to transmit frequencies higher than 0.017 Hz in dogs. Thus we investigated the frequency-response characteristics of the transmission of peripheral sympathetic nerve discharge to peripheral vascular resistance and arterial blood pressure in conscious rats. Eleven rats were instrumented with arterial catheters, nerve electrodes on the sympathetic splanchnic nerve, and flow probes on the superior mesenteric artery. The splanchnic nerve was cut proximal to the electrode to avoid afferent nerve stimulation. The next day the nerve was stimulated at frequencies of 0.05, 0.1, 0.2, 0.5, 1.0, and 2.0 Hz while mesenteric blood flow, BP, and HR were recorded in conscious rats. Mesenteric resistance (MR) was calculated off-line. Nerve stimulation at 0.05, 0.1, 0.2, 0.5, and 1.0 Hz significantly increased the power in MR at these respective frequencies. The greatest response was found between 0.2 and 0.5 Hz. These oscillations in MR were translated to oscillations in BP, but not in HR. Nerve stimulation on the second day, when the nerve was degenerated, did not elicit oscillations in MR or BP. We conclude that the peripheral sympathetic nervous system in rats can transmit signals at frequencies higher than those traditionally assigned to sympathetic vasomotor activity in several species, including humans, and may even overlap with the respiration-related high-frequency range.
Details
- Title: Subtitle
- Frequency response characteristic of sympathetic-mediated vasomotor waves in conscious rats
- Creators
- Harald M Stauss - Department of Exercise Science, University of Iowa, Iowa City 52242, USAKevin C Kregel - Department of Exercise Science, University of Iowa, Iowa City 52242, USA
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.271(4), pp.H1416-H1422
- DOI
- 10.1152/ajpheart.1996.271.4.H1416
- PMID
- 8897935
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Language
- English
- Date published
- 10/01/1996
- Academic Unit
- Radiation Oncology; Provost Office Administration; Health and Human Physiology
- Record Identifier
- 9984213450702771
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