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Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude. / Simpson, Lydia; Steele, Andrew ; Meah, Victoria L.; Thapamagar, Suman; Gasho, Christopher; Drane, Aimee; Oliver, Samuel; Tymko, Michael M.; Ainslie, Philip N.; Steinbeck, Craig D.; Stembridge, Mike; Moore, Jonathan.

In: Faseb Journal, Vol. 33, No. Supplement 1, 562.6, 01.04.2019.

Research output: Contribution to journalMeeting Abstract

HarvardHarvard

Simpson, L, Steele, A, Meah, VL, Thapamagar, S, Gasho, C, Drane, A, Oliver, S, Tymko, MM, Ainslie, PN, Steinbeck, CD, Stembridge, M & Moore, J 2019, 'Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude', Faseb Journal, vol. 33, no. Supplement 1, 562.6.

APA

Simpson, L., Steele, A., Meah, V. L., Thapamagar, S., Gasho, C., Drane, A., ... Moore, J. (2019). Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude. Faseb Journal, 33(Supplement 1), [562.6].

CBE

Simpson L, Steele A, Meah VL, Thapamagar S, Gasho C, Drane A, Oliver S, Tymko MM, Ainslie PN, Steinbeck CD, Stembridge M, Moore J. 2019. Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude. Faseb Journal. 33(Supplement 1).

MLA

VancouverVancouver

Simpson L, Steele A, Meah VL, Thapamagar S, Gasho C, Drane A et al. Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude. Faseb Journal. 2019 Apr 1;33(Supplement 1). 562.6.

Author

Simpson, Lydia ; Steele, Andrew ; Meah, Victoria L. ; Thapamagar, Suman ; Gasho, Christopher ; Drane, Aimee ; Oliver, Samuel ; Tymko, Michael M. ; Ainslie, Philip N. ; Steinbeck, Craig D. ; Stembridge, Mike ; Moore, Jonathan. / Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude. In: Faseb Journal. 2019 ; Vol. 33, No. Supplement 1.

RIS

TY - JOUR

T1 - Selective Reductions in Pulmonary Artery Pressure Lowers Sympathetic Neural Activity in Healthy Humans at High Altitude

AU - Simpson, Lydia

AU - Steele, Andrew

AU - Meah, Victoria L.

AU - Thapamagar, Suman

AU - Gasho, Christopher

AU - Drane, Aimee

AU - Oliver, Samuel

AU - Tymko, Michael M.

AU - Ainslie, Philip N.

AU - Steinbeck, Craig D.

AU - Stembridge, Mike

AU - Moore, Jonathan

PY - 2019/4/1

Y1 - 2019/4/1

N2 - Chronically elevated sympathetic neural activity is a characteristic of many disease states. Tonic chemoreflex activation has been implicated in the development of sympathetic overactivity; however, other reflexes may also contribute. For example, in an animal model, stimulation of pulmonary baroreceptors induces a reflex increase in sympathetic neural activity. In humans, pulmonary pressure has been shown to be related to basal sympathetic activity in pulmonary hypertension; however a critical step in determining a causal link is to establish whether changing pulmonary pressure alters sympathetic outflow. In this pilot study, we exposed thirteen healthy humans (5 females, 28 [ ± 7] years) to high altitude hypoxia (HA; 4383m), a setting known to increase both pulmonary pressure and sympathetic activation, before selectively lowering pulmonary pressure via inhalation of the pulmonary vasodilator nitric oxide. Muscle sympathetic nerve activity (MSNA; Microneurography), blood pressure (BP; Photoplethysmography), heart rate (HR; Electrocardiogram), and peripheral oxygen saturation (SPO2; Pulse oximetry) were continually measured during ambient air breathing (Amb) and during a 6-minute inhalation of nitric oxide (iNO; 40ppm in 21% O2). Pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR) and stroke volume (SV) were determined via cardiac ultrasound. iNO reduced PASP (−23 ± 12%) and PVR (−21 ± 16%) compared to Amb (Table 1). iNO also reduced MSNA burst frequency (−18 ± 18%), burst incidence (−16 ± 17%) and total activity (−21 ± 20%) compared to Amb. MSNA changes during iNO were not related to changes in SPO2 (r = −0.16, P = 0.61) or MAP (r = −0.28, P = 0.35). Our data demonstrate that selectively reducing pulmonary pressure reduces sympathetic nerve activity in healthy humans; therefore, this provides evidence for a causal link in the relationship between pulmonary pressure and basal sympathetic activity. Further investigation is warranted to establish whether elevated pulmonary pressure is a mechanism contributing to chronically elevated sympathetic outflow in disease.

AB - Chronically elevated sympathetic neural activity is a characteristic of many disease states. Tonic chemoreflex activation has been implicated in the development of sympathetic overactivity; however, other reflexes may also contribute. For example, in an animal model, stimulation of pulmonary baroreceptors induces a reflex increase in sympathetic neural activity. In humans, pulmonary pressure has been shown to be related to basal sympathetic activity in pulmonary hypertension; however a critical step in determining a causal link is to establish whether changing pulmonary pressure alters sympathetic outflow. In this pilot study, we exposed thirteen healthy humans (5 females, 28 [ ± 7] years) to high altitude hypoxia (HA; 4383m), a setting known to increase both pulmonary pressure and sympathetic activation, before selectively lowering pulmonary pressure via inhalation of the pulmonary vasodilator nitric oxide. Muscle sympathetic nerve activity (MSNA; Microneurography), blood pressure (BP; Photoplethysmography), heart rate (HR; Electrocardiogram), and peripheral oxygen saturation (SPO2; Pulse oximetry) were continually measured during ambient air breathing (Amb) and during a 6-minute inhalation of nitric oxide (iNO; 40ppm in 21% O2). Pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR) and stroke volume (SV) were determined via cardiac ultrasound. iNO reduced PASP (−23 ± 12%) and PVR (−21 ± 16%) compared to Amb (Table 1). iNO also reduced MSNA burst frequency (−18 ± 18%), burst incidence (−16 ± 17%) and total activity (−21 ± 20%) compared to Amb. MSNA changes during iNO were not related to changes in SPO2 (r = −0.16, P = 0.61) or MAP (r = −0.28, P = 0.35). Our data demonstrate that selectively reducing pulmonary pressure reduces sympathetic nerve activity in healthy humans; therefore, this provides evidence for a causal link in the relationship between pulmonary pressure and basal sympathetic activity. Further investigation is warranted to establish whether elevated pulmonary pressure is a mechanism contributing to chronically elevated sympathetic outflow in disease.

M3 - Meeting Abstract

VL - 33

JO - Faseb Journal

T2 - Faseb Journal

JF - Faseb Journal

SN - 1530-6860

IS - Supplement 1

M1 - 562.6

ER -