Analysis of bronchovascular downstream blood pressure changes in exercising sheep

A. Quail, D. Cottee, D. McLeod, R. Blake, Robert Bishop, S. McIlveen, S. White

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The relative roles of neural and pressure gradient factors, causing a fall or maintenance of bronchial blood flow in exercising sheep, are unknown. These were examined in sheep prepared under thiopentone/isoflurane general anaesthesia with a pulsed Doppler probe mounted on the bronchial artery, and aortic pressure (Pa) catheter in superficial cervical artery. After recovery, Swan-Ganz catheters were inserted under local anaesthesia into the pulmonary artery. Bronchial flow and conductance (Qbr, Cbr), and pressure gradients (Pg; i.e. aortic minus right atrial, Pg_RAP; pulmonary artery, Pg_Ppa; and, left atrial (wedge) Pg_LAP) were derived from continuous records, after switching between downstream sites during and after moderately severe treadmill exercise (3.8km.h-1, for 1.7min, 6min recovery). The protocol was repeated after combined α12-adrenoceptor/ cholinoceptor blockade using phentolamine methanesulfonate and methscopolamine bromide. Bronchial flow fell in both receptor intact (INT) and (BL) blocked state. Pa rose in INT, but downstream pressures rose only 3.7 (RAP), 2.8 (Ppa) and 2.0 (LAP) mmHg (P for each <0.05) in both INT and BL. Pg_RAP and Pg_Ppa did not rise, but Pg_LAP rose 4.0 mmHg (P < 0.05). In BL, Pa fell, as did Pg_RAP (7.0 mmHg, P < 0.05), Pg_Ppa (8.9 mmHg, P < 0.001), but Pg_LAP did not change. Thus, downstream pressures change by small amounts, and pressure gradients to RAP and Ppa sites do not change during moderately severe exercise in normal sheep. The fall in Qbr in INT is due to neural factors, but in BL is due to a fall in Pg. The relative rise in Pg_LAP in both INT and BL favours redistribution within total Qbr to the pulmonary capillary/vein/left atrium site.

Original languageEnglish (US)
Pages (from-to)309-313
Number of pages5
JournalArchives of Physiology and Biochemistry
Volume111
Issue number4
DOIs
StatePublished - Oct 1 2003
Externally publishedYes

Fingerprint

Sheep
Blood Pressure
Pressure
Pulmonary Artery
Catheters
N-Methylscopolamine
Bronchial Arteries
Thiopental
Pulmonary Veins
Phentolamine
Isoflurane
Cholinergic Receptors
Local Anesthesia
Heart Atria
Bromides
General Anesthesia
Adrenergic Receptors
Arterial Pressure
Arteries
Maintenance

Keywords

  • Bronchial blood flow
  • Exercise
  • Pressure gradients
  • Sheep

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Analysis of bronchovascular downstream blood pressure changes in exercising sheep. / Quail, A.; Cottee, D.; McLeod, D.; Blake, R.; Bishop, Robert; McIlveen, S.; White, S.

In: Archives of Physiology and Biochemistry, Vol. 111, No. 4, 01.10.2003, p. 309-313.

Research output: Contribution to journalArticle

Quail, A. ; Cottee, D. ; McLeod, D. ; Blake, R. ; Bishop, Robert ; McIlveen, S. ; White, S. / Analysis of bronchovascular downstream blood pressure changes in exercising sheep. In: Archives of Physiology and Biochemistry. 2003 ; Vol. 111, No. 4. pp. 309-313.
@article{6e25cad586df42488e52b656c88f0830,
title = "Analysis of bronchovascular downstream blood pressure changes in exercising sheep",
abstract = "The relative roles of neural and pressure gradient factors, causing a fall or maintenance of bronchial blood flow in exercising sheep, are unknown. These were examined in sheep prepared under thiopentone/isoflurane general anaesthesia with a pulsed Doppler probe mounted on the bronchial artery, and aortic pressure (Pa) catheter in superficial cervical artery. After recovery, Swan-Ganz catheters were inserted under local anaesthesia into the pulmonary artery. Bronchial flow and conductance (Qbr, Cbr), and pressure gradients (Pg; i.e. aortic minus right atrial, Pg_RAP; pulmonary artery, Pg_Ppa; and, left atrial (wedge) Pg_LAP) were derived from continuous records, after switching between downstream sites during and after moderately severe treadmill exercise (3.8km.h-1, for 1.7min, 6min recovery). The protocol was repeated after combined α1,α2-adrenoceptor/ cholinoceptor blockade using phentolamine methanesulfonate and methscopolamine bromide. Bronchial flow fell in both receptor intact (INT) and (BL) blocked state. Pa rose in INT, but downstream pressures rose only 3.7 (RAP), 2.8 (Ppa) and 2.0 (LAP) mmHg (P for each <0.05) in both INT and BL. Pg_RAP and Pg_Ppa did not rise, but Pg_LAP rose 4.0 mmHg (P < 0.05). In BL, Pa fell, as did Pg_RAP (7.0 mmHg, P < 0.05), Pg_Ppa (8.9 mmHg, P < 0.001), but Pg_LAP did not change. Thus, downstream pressures change by small amounts, and pressure gradients to RAP and Ppa sites do not change during moderately severe exercise in normal sheep. The fall in Qbr in INT is due to neural factors, but in BL is due to a fall in Pg. The relative rise in Pg_LAP in both INT and BL favours redistribution within total Qbr to the pulmonary capillary/vein/left atrium site.",
keywords = "Bronchial blood flow, Exercise, Pressure gradients, Sheep",
author = "A. Quail and D. Cottee and D. McLeod and R. Blake and Robert Bishop and S. McIlveen and S. White",
year = "2003",
month = "10",
day = "1",
doi = "10.1080/13813450312331337469",
language = "English (US)",
volume = "111",
pages = "309--313",
journal = "Archives of Physiology and Biochemistry",
issn = "1381-3455",
publisher = "Informa Healthcare",
number = "4",

}

TY - JOUR

T1 - Analysis of bronchovascular downstream blood pressure changes in exercising sheep

AU - Quail, A.

AU - Cottee, D.

AU - McLeod, D.

AU - Blake, R.

AU - Bishop, Robert

AU - McIlveen, S.

AU - White, S.

PY - 2003/10/1

Y1 - 2003/10/1

N2 - The relative roles of neural and pressure gradient factors, causing a fall or maintenance of bronchial blood flow in exercising sheep, are unknown. These were examined in sheep prepared under thiopentone/isoflurane general anaesthesia with a pulsed Doppler probe mounted on the bronchial artery, and aortic pressure (Pa) catheter in superficial cervical artery. After recovery, Swan-Ganz catheters were inserted under local anaesthesia into the pulmonary artery. Bronchial flow and conductance (Qbr, Cbr), and pressure gradients (Pg; i.e. aortic minus right atrial, Pg_RAP; pulmonary artery, Pg_Ppa; and, left atrial (wedge) Pg_LAP) were derived from continuous records, after switching between downstream sites during and after moderately severe treadmill exercise (3.8km.h-1, for 1.7min, 6min recovery). The protocol was repeated after combined α1,α2-adrenoceptor/ cholinoceptor blockade using phentolamine methanesulfonate and methscopolamine bromide. Bronchial flow fell in both receptor intact (INT) and (BL) blocked state. Pa rose in INT, but downstream pressures rose only 3.7 (RAP), 2.8 (Ppa) and 2.0 (LAP) mmHg (P for each <0.05) in both INT and BL. Pg_RAP and Pg_Ppa did not rise, but Pg_LAP rose 4.0 mmHg (P < 0.05). In BL, Pa fell, as did Pg_RAP (7.0 mmHg, P < 0.05), Pg_Ppa (8.9 mmHg, P < 0.001), but Pg_LAP did not change. Thus, downstream pressures change by small amounts, and pressure gradients to RAP and Ppa sites do not change during moderately severe exercise in normal sheep. The fall in Qbr in INT is due to neural factors, but in BL is due to a fall in Pg. The relative rise in Pg_LAP in both INT and BL favours redistribution within total Qbr to the pulmonary capillary/vein/left atrium site.

AB - The relative roles of neural and pressure gradient factors, causing a fall or maintenance of bronchial blood flow in exercising sheep, are unknown. These were examined in sheep prepared under thiopentone/isoflurane general anaesthesia with a pulsed Doppler probe mounted on the bronchial artery, and aortic pressure (Pa) catheter in superficial cervical artery. After recovery, Swan-Ganz catheters were inserted under local anaesthesia into the pulmonary artery. Bronchial flow and conductance (Qbr, Cbr), and pressure gradients (Pg; i.e. aortic minus right atrial, Pg_RAP; pulmonary artery, Pg_Ppa; and, left atrial (wedge) Pg_LAP) were derived from continuous records, after switching between downstream sites during and after moderately severe treadmill exercise (3.8km.h-1, for 1.7min, 6min recovery). The protocol was repeated after combined α1,α2-adrenoceptor/ cholinoceptor blockade using phentolamine methanesulfonate and methscopolamine bromide. Bronchial flow fell in both receptor intact (INT) and (BL) blocked state. Pa rose in INT, but downstream pressures rose only 3.7 (RAP), 2.8 (Ppa) and 2.0 (LAP) mmHg (P for each <0.05) in both INT and BL. Pg_RAP and Pg_Ppa did not rise, but Pg_LAP rose 4.0 mmHg (P < 0.05). In BL, Pa fell, as did Pg_RAP (7.0 mmHg, P < 0.05), Pg_Ppa (8.9 mmHg, P < 0.001), but Pg_LAP did not change. Thus, downstream pressures change by small amounts, and pressure gradients to RAP and Ppa sites do not change during moderately severe exercise in normal sheep. The fall in Qbr in INT is due to neural factors, but in BL is due to a fall in Pg. The relative rise in Pg_LAP in both INT and BL favours redistribution within total Qbr to the pulmonary capillary/vein/left atrium site.

KW - Bronchial blood flow

KW - Exercise

KW - Pressure gradients

KW - Sheep

UR - http://www.scopus.com/inward/record.url?scp=14344264096&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=14344264096&partnerID=8YFLogxK

U2 - 10.1080/13813450312331337469

DO - 10.1080/13813450312331337469

M3 - Article

VL - 111

SP - 309

EP - 313

JO - Archives of Physiology and Biochemistry

JF - Archives of Physiology and Biochemistry

SN - 1381-3455

IS - 4

ER -