Interactions of plasma osmolality with arterial and central venous pressures in control of sympathetic activity and heart rate in humans

N. Charkoudian, J. H. Eisenach, Michael Joseph Joyner, S. K. Roberts, D. E. Wick

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Plasma osmolality alters control of sympathetic activity and heart rate in animal models; however, it is unknown whether physiological increases in plasma osmolality have such influences in humans and what effect concurrent changes in central venous and/or arterial pressures may have. We tested whether physiological increases in plasma osmolality (similar to those during exercise dehydration) alter control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) in humans. We studied 17 healthy young adults (7 women, 10 men) at baseline and during arterial pressure (AP) transients induced by sequential injections of nitroprusside and phenylephrine, under three conditions: control (C), after 1 ml/kg intravenous hypertonic saline (HT1), and after 2 ml/kg hypertonic saline (HT2). We continuously measured HR, AP, central venous pressure (CVP; peripherally inserted central catheter) and MSNA (peroneal microneurography) in all conditions. Plasma osmolality increased from 287 ± 1 mosmol/kg in C to 290 ± 1 mosmol/kg in HT1 (P < 0.05) but did not increase further in HT2 (291 ± 1 mosmol/kg; P > 0.05 vs. C). Mean AP and CVP were similar between C and HT1, but both increased slightly in HT2. HR increased slightly but significantly during both HT1 and HT2 vs. C (P < 0.05). Sensitivity of baroreflex control of MSNA was significantly increased vs. C in HT1 [-7.59 ± 0.97 (HT1) vs. -5.85 ± 0.63 (C) arbitrary units (au)·beat-1·mmHg-1; P < 0.01] but was not different in HT2 (-6.55 ± 0.94 au·beat -1·mmHg-1). We conclude that physiological changes in plasma osmolality significantly alter control of MSNA and HR in humans, and that this influence can be modified by CVP and AP.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume289
Issue number6 58-6
DOIs
StatePublished - Dec 2005

Fingerprint

Central Venous Pressure
Osmolar Concentration
Arterial Pressure
Heart Rate
Muscles
Peroneal Nerve
Baroreflex
Nitroprusside
Phenylephrine
Dehydration
Young Adult
Catheters
Animal Models
Exercise
Injections

Keywords

  • Baroreflex
  • Hydration
  • Plasma volume
  • Sympathetic nervous system

ASJC Scopus subject areas

  • Physiology

Cite this

Interactions of plasma osmolality with arterial and central venous pressures in control of sympathetic activity and heart rate in humans. / Charkoudian, N.; Eisenach, J. H.; Joyner, Michael Joseph; Roberts, S. K.; Wick, D. E.

In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 289, No. 6 58-6, 12.2005.

Research output: Contribution to journalArticle

@article{e3e3c1e69d4b4605be0697a23f72b969,
title = "Interactions of plasma osmolality with arterial and central venous pressures in control of sympathetic activity and heart rate in humans",
abstract = "Plasma osmolality alters control of sympathetic activity and heart rate in animal models; however, it is unknown whether physiological increases in plasma osmolality have such influences in humans and what effect concurrent changes in central venous and/or arterial pressures may have. We tested whether physiological increases in plasma osmolality (similar to those during exercise dehydration) alter control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) in humans. We studied 17 healthy young adults (7 women, 10 men) at baseline and during arterial pressure (AP) transients induced by sequential injections of nitroprusside and phenylephrine, under three conditions: control (C), after 1 ml/kg intravenous hypertonic saline (HT1), and after 2 ml/kg hypertonic saline (HT2). We continuously measured HR, AP, central venous pressure (CVP; peripherally inserted central catheter) and MSNA (peroneal microneurography) in all conditions. Plasma osmolality increased from 287 ± 1 mosmol/kg in C to 290 ± 1 mosmol/kg in HT1 (P < 0.05) but did not increase further in HT2 (291 ± 1 mosmol/kg; P > 0.05 vs. C). Mean AP and CVP were similar between C and HT1, but both increased slightly in HT2. HR increased slightly but significantly during both HT1 and HT2 vs. C (P < 0.05). Sensitivity of baroreflex control of MSNA was significantly increased vs. C in HT1 [-7.59 ± 0.97 (HT1) vs. -5.85 ± 0.63 (C) arbitrary units (au)·beat-1·mmHg-1; P < 0.01] but was not different in HT2 (-6.55 ± 0.94 au·beat -1·mmHg-1). We conclude that physiological changes in plasma osmolality significantly alter control of MSNA and HR in humans, and that this influence can be modified by CVP and AP.",
keywords = "Baroreflex, Hydration, Plasma volume, Sympathetic nervous system",
author = "N. Charkoudian and Eisenach, {J. H.} and Joyner, {Michael Joseph} and Roberts, {S. K.} and Wick, {D. E.}",
year = "2005",
month = "12",
doi = "10.1152/ajpheart.00601.2005",
language = "English (US)",
volume = "289",
journal = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
issn = "1931-857X",
publisher = "American Physiological Society",
number = "6 58-6",

}

TY - JOUR

T1 - Interactions of plasma osmolality with arterial and central venous pressures in control of sympathetic activity and heart rate in humans

AU - Charkoudian, N.

AU - Eisenach, J. H.

AU - Joyner, Michael Joseph

AU - Roberts, S. K.

AU - Wick, D. E.

PY - 2005/12

Y1 - 2005/12

N2 - Plasma osmolality alters control of sympathetic activity and heart rate in animal models; however, it is unknown whether physiological increases in plasma osmolality have such influences in humans and what effect concurrent changes in central venous and/or arterial pressures may have. We tested whether physiological increases in plasma osmolality (similar to those during exercise dehydration) alter control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) in humans. We studied 17 healthy young adults (7 women, 10 men) at baseline and during arterial pressure (AP) transients induced by sequential injections of nitroprusside and phenylephrine, under three conditions: control (C), after 1 ml/kg intravenous hypertonic saline (HT1), and after 2 ml/kg hypertonic saline (HT2). We continuously measured HR, AP, central venous pressure (CVP; peripherally inserted central catheter) and MSNA (peroneal microneurography) in all conditions. Plasma osmolality increased from 287 ± 1 mosmol/kg in C to 290 ± 1 mosmol/kg in HT1 (P < 0.05) but did not increase further in HT2 (291 ± 1 mosmol/kg; P > 0.05 vs. C). Mean AP and CVP were similar between C and HT1, but both increased slightly in HT2. HR increased slightly but significantly during both HT1 and HT2 vs. C (P < 0.05). Sensitivity of baroreflex control of MSNA was significantly increased vs. C in HT1 [-7.59 ± 0.97 (HT1) vs. -5.85 ± 0.63 (C) arbitrary units (au)·beat-1·mmHg-1; P < 0.01] but was not different in HT2 (-6.55 ± 0.94 au·beat -1·mmHg-1). We conclude that physiological changes in plasma osmolality significantly alter control of MSNA and HR in humans, and that this influence can be modified by CVP and AP.

AB - Plasma osmolality alters control of sympathetic activity and heart rate in animal models; however, it is unknown whether physiological increases in plasma osmolality have such influences in humans and what effect concurrent changes in central venous and/or arterial pressures may have. We tested whether physiological increases in plasma osmolality (similar to those during exercise dehydration) alter control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) in humans. We studied 17 healthy young adults (7 women, 10 men) at baseline and during arterial pressure (AP) transients induced by sequential injections of nitroprusside and phenylephrine, under three conditions: control (C), after 1 ml/kg intravenous hypertonic saline (HT1), and after 2 ml/kg hypertonic saline (HT2). We continuously measured HR, AP, central venous pressure (CVP; peripherally inserted central catheter) and MSNA (peroneal microneurography) in all conditions. Plasma osmolality increased from 287 ± 1 mosmol/kg in C to 290 ± 1 mosmol/kg in HT1 (P < 0.05) but did not increase further in HT2 (291 ± 1 mosmol/kg; P > 0.05 vs. C). Mean AP and CVP were similar between C and HT1, but both increased slightly in HT2. HR increased slightly but significantly during both HT1 and HT2 vs. C (P < 0.05). Sensitivity of baroreflex control of MSNA was significantly increased vs. C in HT1 [-7.59 ± 0.97 (HT1) vs. -5.85 ± 0.63 (C) arbitrary units (au)·beat-1·mmHg-1; P < 0.01] but was not different in HT2 (-6.55 ± 0.94 au·beat -1·mmHg-1). We conclude that physiological changes in plasma osmolality significantly alter control of MSNA and HR in humans, and that this influence can be modified by CVP and AP.

KW - Baroreflex

KW - Hydration

KW - Plasma volume

KW - Sympathetic nervous system

UR - http://www.scopus.com/inward/record.url?scp=28144464079&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=28144464079&partnerID=8YFLogxK

U2 - 10.1152/ajpheart.00601.2005

DO - 10.1152/ajpheart.00601.2005

M3 - Article

C2 - 16199481

AN - SCOPUS:28144464079

VL - 289

JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

SN - 1931-857X

IS - 6 58-6

ER -