TY - JOUR
T1 - Sympathetic neural regulation of heart rate is robust against high plasma catecholamines
AU - Kawada, Toru
AU - Miyamoto, Tadayoshi
AU - Miyoshi, Yuichiro
AU - Yamaguchi, Sayo
AU - Tanabe, Yukiko
AU - Kamiya, Atsunori
AU - Shishido, Toshiaki
AU - Sugimachi, Masaru
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2006/6
Y1 - 2006/6
N2 - The sympathetic regulation of heart rate (HR) may be attained by neural and humoral factors. With respect to the humoral factor, plasma noradrenaline (NA) and adrenaline (Adr) can reportedly increase to levels approximately 10 times higher than resting level during severe exercise. Whether such high plasma NA or Adr interfered with the sympathetic neural regulation of HR remained unknown. We estimated the transfer function from cardiac sympathetic nerve stimulation (SNS) to HR in anesthetized and vagotomized rabbits. An intravenous administration of NA (n = 6) at 1 and 10 μg·kg -1·h -1 increased plasma NA concentration (pg/ml) from a baseline level of 438 ± 117 (mean ± SE) to 974 ± 106 and 6,830 ± 917 (P < 0.01), respectively. The dynamic gain (bpm/Hz) of the transfer function did not change significantly (from 7.6 ± 1.2 to 7.5 ± 1.1 and 8.1 ± 1.1), whereas mean HR (in bpm) during SNS slightly increased from 280 ± 24 to 289 ± 22 (P < 0.01) and 288 ± 22 (P < 0.01). The intravenous administration of Adr (n = 6) at 1 and 10 μg·kg -1·h -1increased plasma Adr concentration (pg/ml) from a baseline level of 257 ± 86 to 659 ± 172 and 2,760 ± 590 (P < 0.01), respectively. Neither the dynamic gain (from 8.0 ± 0.6 to 8.4 ± 0.8 and 8.2 ± 1.0) nor the mean HR during SNS (from 274 ± 13 to 275 ±13 and 274 ± 13) changed significantly. In contrast, the intravenous administration of isoproterenol (n = 6) at 10 μg·kg -1·h -1significantly increased mean HR during SNS (from 278 ± 11 to 293 ± 9, P < 0.01) and blunted the transfer gain value at 0.0078 Hz (from 5.9 ± 1.0 to 1.0 ± 0.4, P < 0.01). In conclusion, high plasma NA or Adr hardly affected the dynamic sympathetic neural regulation of HR.
AB - The sympathetic regulation of heart rate (HR) may be attained by neural and humoral factors. With respect to the humoral factor, plasma noradrenaline (NA) and adrenaline (Adr) can reportedly increase to levels approximately 10 times higher than resting level during severe exercise. Whether such high plasma NA or Adr interfered with the sympathetic neural regulation of HR remained unknown. We estimated the transfer function from cardiac sympathetic nerve stimulation (SNS) to HR in anesthetized and vagotomized rabbits. An intravenous administration of NA (n = 6) at 1 and 10 μg·kg -1·h -1 increased plasma NA concentration (pg/ml) from a baseline level of 438 ± 117 (mean ± SE) to 974 ± 106 and 6,830 ± 917 (P < 0.01), respectively. The dynamic gain (bpm/Hz) of the transfer function did not change significantly (from 7.6 ± 1.2 to 7.5 ± 1.1 and 8.1 ± 1.1), whereas mean HR (in bpm) during SNS slightly increased from 280 ± 24 to 289 ± 22 (P < 0.01) and 288 ± 22 (P < 0.01). The intravenous administration of Adr (n = 6) at 1 and 10 μg·kg -1·h -1increased plasma Adr concentration (pg/ml) from a baseline level of 257 ± 86 to 659 ± 172 and 2,760 ± 590 (P < 0.01), respectively. Neither the dynamic gain (from 8.0 ± 0.6 to 8.4 ± 0.8 and 8.2 ± 1.0) nor the mean HR during SNS (from 274 ± 13 to 275 ±13 and 274 ± 13) changed significantly. In contrast, the intravenous administration of isoproterenol (n = 6) at 10 μg·kg -1·h -1significantly increased mean HR during SNS (from 278 ± 11 to 293 ± 9, P < 0.01) and blunted the transfer gain value at 0.0078 Hz (from 5.9 ± 1.0 to 1.0 ± 0.4, P < 0.01). In conclusion, high plasma NA or Adr hardly affected the dynamic sympathetic neural regulation of HR.
KW - Adrenaline
KW - Isoproterenol
KW - Neuro-humoral interaction
KW - Noradrenaline
KW - Systems analysis
UR - http://www.scopus.com/inward/record.url?scp=39049189381&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=39049189381&partnerID=8YFLogxK
U2 - 10.2170/physiolsci.RP006006
DO - 10.2170/physiolsci.RP006006
M3 - Article
C2 - 16839462
AN - SCOPUS:39049189381
VL - 56
SP - 235
EP - 245
JO - Journal of Physiological Sciences
JF - Journal of Physiological Sciences
SN - 1880-6546
IS - 3
ER -