scholarly journals The distribution of blood flow, oxygen consumption, and work output among the respiratory muscles during unobstructed hyperventilation.

1977 ◽  
Vol 59 (1) ◽  
pp. 43-50 ◽  
Author(s):  
C H Robertson ◽  
M A Pagel ◽  
R L Johnson
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Respiratory Muscles ◽  
Work Output

alpha-Adrenergic control of oxygen delivery to myocardium during exercise in conscious dogs

1982 ◽  
Vol 242 (5) ◽  
pp. H805-H809 ◽  
Author(s):  
G. R. Heyndrickx ◽  
P. Muylaert ◽  
J. L. Pannier
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Coronary Blood Flow ◽  
Coronary Sinus ◽  
Oxygen Delivery ◽  
Left Ventricular ◽  
Conscious Dogs ◽  
Adrenergic Blockade ◽  
Adrenergic Control

alpha-Adrenergic control of the oxygen delivery to the myocardium during exercise was investigated in eight conscious dogs instrumented for chronic measurements of coronary blood flow, left ventricular (LV) pressure, aortic blood pressure, and heart rate and sampling of arterial and coronary sinus blood. After alpha-adrenergic receptor blockade a standard exercise load elicited a significantly greater increase in heart rate, rate of change of LV pressure (LV dP/dt), LV dP/dt/P, and coronary blood flow than was elicited in the unblocked state. In contrast to the response pattern during control exercise, there was no significant change in coronary sinus oxygen tension (PO2), myocardial arteriovenous oxygen difference, and myocardial oxygen delivery-to-oxygen consumption ratio. It is concluded that the normal relationship between myocardial oxygen supply and oxygen demand is modified during exercise after alpha-adrenergic blockade, whereby oxygen delivery is better matched to oxygen consumption. These results indicate that the increase in coronary blood flow and oxygen delivery to the myocardium during normal exercise is limited by alpha-adrenergic vasoconstriction.

Effects of nicotine on canine intestinal blood flow and oxygen consumption

1984 ◽  
Vol 246 (2) ◽  
pp. G195-G203
Author(s):  
R. H. Gallavan ◽  
Y. Tsuchiya ◽  
E. D. Jacobson
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Muscle Tension ◽  
Intestinal Blood Flow ◽  
Mesenteric Blood Flow ◽  
State Response ◽  
Arterial Blood ◽  
Intestinal Circulation

The purpose of this study was to determine the effects of nicotine on intestinal blood flow and oxygen consumption. The intravenous infusion of nicotine at doses corresponding to those experienced by smokers produced a transient increase in systemic arterial blood pressure and mesenteric blood flow. Subsequently a steady-state response developed that consisted of a reduction in mesenteric blood flow due to both a decrease in blood pressure and an increase in intestinal vascular resistance. This increase in resistance was probably due to increased levels of circulating catecholamines. The intra-arterial infusion of nicotine into the intestinal circulation at doses experienced by the average smoker had no effect on either intestinal blood flow or oxygen consumption. Similarly, under in vitro conditions nicotine had no direct effect on intestinal vascular smooth muscle tension. Thus, nicotine appears to reduce intestinal blood flow indirectly as a result of its systemic effects.

EFFECTS OF HYPEROXEMIA ON MYOCARDIAL BLOOD FLOW AND OXYGEN CONSUMPTION IN AN ISOLATED RABBIT HEART

1988 ◽  
Vol 69 (3A) ◽  
pp. A216-A216 ◽  
Author(s):  
J. F. Baron ◽  
E. Vicaut ◽  
X. HOU ◽  
P. Vlars ◽  
M. Duvelleroy
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Myocardial Blood Flow ◽  
Rabbit Heart ◽  
Isolated Rabbit Heart

Metabolic responses of the whole body, portal-drained viscera and hindquarter to adrenaline infusion: Effects of nonselective and selective β-adrenoceptor blockade

1997 ◽  
Vol 77 (2) ◽  
pp. 307-316 ◽  
Author(s):  
J. O. O. Miaron ◽  
R. J. Christopherson
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Portal Vein ◽  
Influencing Factor ◽  
External Iliac Artery ◽  
Open Circuit ◽  
Whole Body ◽  
Organ Blood Flow ◽  
Β Blocker ◽  
Β Blockers

Propranolol, a nonselective β-blocker and selective β-blockers (metoprolol a β1-blocker and ICI 118551 a β2-blocker) were used to investigate the β-adrenoceptor-mediated adrenaline-induced increase in whole-body and organ VO2 in five whether sheep. Transit time blood flow probes were chronically implanted on the portal vein and the external iliac artery and sampling catheters were placed in the mesenteric artery, iliac vein and portal vein. Oxygen consumption by the whole body was measured by open circuit calorimetry, and oxygen consumption by the portal-drained viscera and the hindquarter was determined from A-VO2 differences and organ blood flow. Absolute pre-infusion VO2 values for the whole body, portal-drained viscera and hindquarters were 236 ± 7.4, 61 ± 6.0 and 13 ± 3.1 mL min−1 respectively. The mean changes in VO2 in response to infusion were 74 vs. 11, 26, 10 and 12 mL min−1 (SE = 9.1) for whole body; 31 vs. −2, −15, 13 and −4 mL min−1 (SE = 7.3) for portal-drained viscera and 8 vs. −0.4, 2.1, 1.0 and −2.7 mL min−1; SE = 4.3) for hindquarters during adrenaline, control, propranolol, metoprolol and ICI 118551 treatments, respectively. Adrenaline increased VO2 (P < 0.05) in the whole body and portal-drained viscera, but not hindquarters relative to controls. All β-blockers suppressed (P < 0.05) the adrenaline-induced increase in VO2 except for the portal-drained viscera where metoprolol was less effective and the hindquarters where β-blockers had no effect. The blood flow pattern was similar to VO2 responses for the portal-drained viscera. The nonselective β1 and β2 blockers were effective in reducing the adrenaline-induced increases in blood flow from the portal-drained viscera and to the hindquarters, with more pronounced β-adrenoceptor-mediated haemodynamic effects. The results indicate that the β-adrenoceptor system modulates whole body VO2, clearly establishes that adrenaline induces an increased VO2 in portal-drained viscera which can be reversed by a β2 or nonselective β blocker and implicates β adrenoceptors as an influencing factor in the maintenance energy requirements of ruminants. Key words: Calorimetry, adrenaline, β blockers, blood flow, sheep

Effects of Walking with Blood Flow Restriction on Excess Post-exercise Oxygen Consumption

2015 ◽  
Vol 36 (03) ◽  
pp. e11-e18 ◽  
Author(s):  
G. Mendonca ◽  
J. Vaz ◽  
P. Pezarat-Correia ◽  
B. Fernhall
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Relative Intensity ◽  
Walking Speed ◽  
Treadmill Exercise ◽  
Young Men ◽  
Blood Flow Restriction ◽  
Post Exercise ◽  
Flow Restriction ◽  
O2 Deficit

AbstractThis study determined the influence of walking with blood flow restriction (BFR) on the excess post-exercise oxygen consumption (EPOC) of healthy young men. 17 healthy young men (22.1±2.9 years) performed graded treadmill exercise to assess VO2peak. In a randomized fashion, each participant performed 5 sets of 3-min treadmill exercise at their optimal walking speed with 1-min interval either with or without BFR. Participants were then seated in a chair and remained there for 30 min of recovery. Expired gases were continuously monitored during exercise and recovery. BFR increased the O2 cost of walking as well as its relative intensity and cumulative O2 deficit (p<0.05). The EPOC magnitude after walking with BFR was greater than in the non-BFR condition (p<0.05). No differences between conditions were seen for the duration of EPOC. The EPOC magnitude was no longer different between conditions after controlling for the differences in relative intensity and in the cumulative O2 deficit (p>0.05). These data indicate that walking with BFR increases the magnitude of EPOC. Moreover, they also demonstrate that such increment in EPOC is likely explained by the effects of BFR on walking relative intensity and cumulative O2 deficit.

Local blood flow, oxygen tension, and oxygen consumption in the rat spinal cord

1983 ◽  
Vol 58 (4) ◽  
pp. 526-530 ◽  
Author(s):  
Nariyuki Hayashi ◽  
Barth A. Green ◽  
Mayra Gonzalez-Carvajal ◽  
Joseph Mora ◽  
Richard P. Veraa
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Oxygen Tension ◽  
Tissue Oxygen ◽  
Local Blood Flow ◽  
Rat Spinal Cord ◽  
Spinal Cord Blood Flow ◽  
Content Type ◽  
Tissue Oxygen Consumption

✓ Using a reliable and reproducible microelectrode technique, consistent simultaneous measurements of local spinal cord blood flow (SCBF), tissue oxygen tension, and tissue oxygen consumption were made at cervical, thoracic, and lumbar levels in the rat spinal cord. These observations showed that the metabolic state is maintained constant along the cord, despite significant variations in vasculature. The physiological and anatomical aspects of these findings are discussed.

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