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Differential responses of frequency components of renal sympathetic nerve activity to arterial pressure changes in conscious rats.
Am J Physiol Regul Integr Comp Physiol. 2005 Oct; 289(4):R1074-82.AJ

Abstract

The present study examined the effects of baroreceptor loading and unloading on the various rhythms present in the renal sympathetic nerve activity (RSNA) of 10 conscious rats. Short-lasting (4-5 min), steady-state decreases (from -10 to -40 mmHg) and increases (from 5 to 30 mmHg) in arterial pressure (AP) were induced by the intravenous infusion of sodium nitroprusside and phenylephrine, respectively. The relationship between changes in AP level and RSNA total power (fast Fourier transform analysis; 0-25 Hz) was characterized by an inverse sigmoid function. Basal AP was located 6.3 mmHg above AP at the midrange of the curve, that is, near the lower plateau. Sigmoid relationships were also observed for spectral powers in the low (LF, 0.030-0.244 Hz), respiratory (0.79-2.5 Hz) and high-frequency (HF, 2.5-25 Hz) bands. In contrast, in the MF band (0.27-0.76 Hz) containing oscillations associated with Mayer waves, the AP-RSNA power relationship showed a bell curve shape with a maximum at 21 mmHg below basal AP. Similarly, changes in RSNA power at the frequency of the heart beat were well characterized by a bell curve reaching a maximum at 22 mmHg below basal AP. Under baseline conditions, LF, MF, respiratory and HF powers contributed approximately 3, 10, 18, and 69% of the total RSNA power, respectively. The pulse-synchronous oscillation of RSNA accounted for only 11 +/- 1% of HF power. The contribution of HF power to total power did not change consistently with AP changes. Therefore, most of the baroreflex-induced changes in RSNA are mediated by changes in the amplitude of fast, irregular fluctuations.

Authors+Show Affiliations

Département de Physiologie et Pharmacologie Clinique, Faculté de Pharmacie, Université Claude Bernard Lyon 1, Lyon, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

15932970

Citation

Bertram, Delphine, et al. "Differential Responses of Frequency Components of Renal Sympathetic Nerve Activity to Arterial Pressure Changes in Conscious Rats." American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, vol. 289, no. 4, 2005, pp. R1074-82.
Bertram D, Oréa V, Chapuis B, et al. Differential responses of frequency components of renal sympathetic nerve activity to arterial pressure changes in conscious rats. Am J Physiol Regul Integr Comp Physiol. 2005;289(4):R1074-82.
Bertram, D., Oréa, V., Chapuis, B., Barrès, C., & Julien, C. (2005). Differential responses of frequency components of renal sympathetic nerve activity to arterial pressure changes in conscious rats. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 289(4), R1074-82.
Bertram D, et al. Differential Responses of Frequency Components of Renal Sympathetic Nerve Activity to Arterial Pressure Changes in Conscious Rats. Am J Physiol Regul Integr Comp Physiol. 2005;289(4):R1074-82. PubMed PMID: 15932970.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Differential responses of frequency components of renal sympathetic nerve activity to arterial pressure changes in conscious rats. AU - Bertram,Delphine, AU - Oréa,Valérie, AU - Chapuis,Bruno, AU - Barrès,Christian, AU - Julien,Claude, Y1 - 2005/06/02/ PY - 2005/6/4/pubmed PY - 2005/11/8/medline PY - 2005/6/4/entrez SP - R1074 EP - 82 JF - American journal of physiology. Regulatory, integrative and comparative physiology JO - Am. J. Physiol. Regul. Integr. Comp. Physiol. VL - 289 IS - 4 N2 - The present study examined the effects of baroreceptor loading and unloading on the various rhythms present in the renal sympathetic nerve activity (RSNA) of 10 conscious rats. Short-lasting (4-5 min), steady-state decreases (from -10 to -40 mmHg) and increases (from 5 to 30 mmHg) in arterial pressure (AP) were induced by the intravenous infusion of sodium nitroprusside and phenylephrine, respectively. The relationship between changes in AP level and RSNA total power (fast Fourier transform analysis; 0-25 Hz) was characterized by an inverse sigmoid function. Basal AP was located 6.3 mmHg above AP at the midrange of the curve, that is, near the lower plateau. Sigmoid relationships were also observed for spectral powers in the low (LF, 0.030-0.244 Hz), respiratory (0.79-2.5 Hz) and high-frequency (HF, 2.5-25 Hz) bands. In contrast, in the MF band (0.27-0.76 Hz) containing oscillations associated with Mayer waves, the AP-RSNA power relationship showed a bell curve shape with a maximum at 21 mmHg below basal AP. Similarly, changes in RSNA power at the frequency of the heart beat were well characterized by a bell curve reaching a maximum at 22 mmHg below basal AP. Under baseline conditions, LF, MF, respiratory and HF powers contributed approximately 3, 10, 18, and 69% of the total RSNA power, respectively. The pulse-synchronous oscillation of RSNA accounted for only 11 +/- 1% of HF power. The contribution of HF power to total power did not change consistently with AP changes. Therefore, most of the baroreflex-induced changes in RSNA are mediated by changes in the amplitude of fast, irregular fluctuations. SN - 0363-6119 UR - https://www.unboundmedicine.com/medline/citation/15932970/Differential_responses_of_frequency_components_of_renal_sympathetic_nerve_activity_to_arterial_pressure_changes_in_conscious_rats_ L2 - http://www.physiology.org/doi/full/10.1152/ajpregu.00270.2005?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -