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    Dynamic baroreflex control of blood pressure: influence of the heart vs. peripheral resistance


    Liu, Huang-Ku and Guild, Sarah-Jane and Ringwood, John and Barrett, Carolyn J. and Leonard, Bridget L. and Nguang, Sing-Kiong and Navakatikyan, Michael and Malpas, Simon C. (2002) Dynamic baroreflex control of blood pressure: influence of the heart vs. peripheral resistance. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, 283 (2). pp. 533-542. ISSN 0002-9513

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    Abstract

    The aim in the present experiments was to assess the dynamic baroreflex control of blood pressure, to develop an accurate mathematical model that represented this relationship, and to assess the role of dynamic changes in heart rate and stroke volume in giving rise to components of this response. Patterned electrical stimulation [pseudo-random binary sequence (PRBS)] was applied to the aortic depressor nerve (ADN) to produce changes in blood pressure under open-loop conditions in anesthetized rabbits. The stimulus provided constant power over the frequency range 0–0.5 Hz and revealed that the composite systems represented by the central nervous system, sympathetic activity, and vascular resistance responded as a second-order low-pass filter (corner frequency ≈0.047 Hz) with a time delay (1.01 s). The gain between ADN and mean arterial pressure was reasonably constant before the corner frequency and then decreased with increasing frequency of stimulus. Although the heart rate was altered in response to the PRBS stimuli, we found that removal of the heart's ability to contribute to blood pressure variability by vagotomy and β1-receptor blockade did not significantly alter the frequency response. We conclude that the contribution of the heart to the dynamic regulation of blood pressure is negligible in the rabbit. The consequences of this finding are examined with respect to low-frequency oscillations in blood pressure.

    Item Type: Article
    Keywords: sympathetic nerve activity; modeling; transfer function; vasculature; rabbit;
    Academic Unit: Faculty of Science and Engineering > Electronic Engineering
    Item ID: 6910
    Identification Number: https://doi.org/10.1152/ajpregu.00489.2001
    Depositing User: Professor John Ringwood
    Date Deposited: 21 Jan 2016 12:35
    Journal or Publication Title: American Journal of Physiology: Regulatory, Integrative and Comparative Physiology
    Publisher: American Physiological Society
    Refereed: Yes
    URI:

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