Cardiovascular and metabolic responses to low dose adrenaline infusion: an invasive study in humans

1986 ◽  
Vol 70 (2) ◽  
pp. 199-206 ◽  
Author(s):  
U. Freyschuss ◽  
P. Hjemdahl ◽  
A. Juhlin-Dannfelt ◽  
B. Linde
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Adipose Tissue ◽  
Cardiac Output ◽  
Cyclic Amp ◽  
Plasma Concentrations ◽  
Metabolic Responses ◽  
Tissue Blood Flow ◽  
Arterial Plasma

1. Cardiovascular and metabolic responses to intravenous infusions of adrenaline (ADR), which raised arterial plasma ADR in a stepwise fashion from 0.3 to 1.3, 2.3 and 6.0 nmol/l, were studied in 11 healthy volunteers. 2. ADR evoked marked and concentration-dependent increases in stroke volume and cardiac output (thermodilution), as well as decreases in the vascular resistances of the systemic circulation, calf and adipose tissue. These changes were significant from 1.3 nmol/l ADR. Less marked effects were found on blood pressure and heart rate. 3. Significant arterial ADR concentration-effect relationships were found for cyclic AMP, glycerol, glucose, lactate and noradrenaline, but not for insulin. Cyclic AMP and glycerol were significantly elevated at 1.3, glucose at 2.3, but lactate not below 6.0 nmol/l ADR. Increases in adipose tissue blood flow and arterial glycerol levels were correlated (P < 0.001), suggesting a metabolic component in the blood flow response of adipose tissue. 4. Invasive haemodynamic measurements revealed that ADR at arterial concentrations within the lower physiological range had considerable effects on cardiac output and vascular resistances, despite moderate changes in the conventional non-invasive haemodynamic variables blood pressure and heart rate. 5. ADR elicited clear-cut responses at arterial plasma concentrations attained during various kinds of mild to moderate stress.

Hemodynamic effects of weight reduction in the obese rat

1984 ◽  
Vol 247 (2) ◽  
pp. R266-R271
Author(s):  
D. L. Crandall ◽  
B. M. Goldstein ◽  
R. A. Gabel ◽  
P. Cervoni
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Body Weight ◽  
Adipose Tissue ◽  
Cardiac Output ◽  
Weight Reduction ◽  
Left Ventricular ◽  
Tissue Blood Flow ◽  
Arterial Blood ◽  
Obese Rats

The effect of defined increments of weight loss on hemodynamics has been investigated in conscious, unrestrained, spontaneously obese rats. Obese rats were subjected to a calorically restricted diet and were used for experimentation on achieving a 10, 20, or 30% reduction in body weight. After monitoring resting blood pressure and heart rate, radioactive microspheres were infused for determination of blood flow distribution. Of 10 organs sample, only heart, liver, kidneys, and 2 adipose tissue depots exhibited significant decreases in weight associated with body weight reduction. Mean arterial blood pressure remained unchanged, while stroke volume, left ventricular work, and cardiac output decreased significantly. Blood flow decreased to kidneys, testes, and adipose tissue through a 30% reduction in body weight, but the fractional distribution of cardiac output decreased only to adipose tissue. Therefore the large decreases in renal and adipose tissue blood flow during weight reduction may contribute to the associated decrease in cardiac output. Of those vascular beds examined, however, both absolute and relative blood flow decreased only to adipose tissue, thus denoting the influence of fat mass on hemodynamics during obesity.

Adipocyte blood flow is decreased in obese Zucker rats

1987 ◽  
Vol 253 (2) ◽  
pp. R228-R233 ◽  
Author(s):  
D. B. West ◽  
W. A. Prinz ◽  
A. A. Francendese ◽  
M. R. Greenwood
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Adipose Tissue ◽  
Cardiac Output ◽  
Triceps Surae ◽  
Zucker Rats ◽  
Tissue Blood Flow ◽  
Organ Blood Flow ◽  
Fat Depots ◽  
Obese Rats

Blood flow to five adipose tissue depots and five other organs was measured in unanesthetized free-moving obese and lean male Zucker rats using the radiolabeled microsphere technique. Cardiac output and blood pressure were also measured. Obese rats were significantly heavier and had larger fat depots characterized by more and larger adipocytes. Cardiac output and blood pressure were similar in lean and obese rats. Blood flow to adipose tissue was substantially reduced in all five depots of obese rats when expressed per square millimeter of cell surface. When blood flow was expressed per cell, it was reduced in obese rats in the dorsal subcutaneous and inguinal depots and significantly elevated in the obese mesenteric adipose depot. Significant interdepot differences in blood flow were observed in both lean and obese rats. Nonadipose organ blood flow was not different between obese and lean rats, but when expressed on a per gram basis, blood flow through triceps surae muscle, epididymis, and testis was elevated in obese rats. These findings suggest that there is a substantial alteration of hemodynamics in obesity that may contribute to or reflect the altered metabolism of adipose tissue in obese rats. Furthermore, interdepot differences of adipose tissue blood flow also parallel reported interdepot differences in metabolism.

Nocturnal variations in peripheral blood flow, systemic blood pressure, and heart rate in humans

1991 ◽  
Vol 261 (4) ◽  
pp. H982-H988
Author(s):  
J. H. Sindrup ◽  
J. Kastrup ◽  
H. Christensen ◽  
B. Jorgensen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Arterial Blood Pressure ◽  
Flow Rate ◽  
Mean Arterial Blood Pressure ◽  
Blood Flow Rate ◽  
Tissue Blood Flow ◽  
Peripheral Blood Flow ◽  
Arterial Blood

Subcutaneous adipose tissue blood flow rate, together with systemic arterial blood pressure and heart rate under ambulatory conditions, was measured in the lower legs of 15 normal human subjects for 12-20 h. The 133Xe-washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used for measurement of blood flow rates. An automatic portable blood pressure recorder and processor unit was used for measurement of systolic blood pressure, diastolic blood pressure, and heart rate every 15 min. The change from upright to supine position at the beginning of the night period was associated with a 30-40% increase in blood flow rate and a highly significant decrease in mean arterial blood pressure and heart rate (P less than 0.001 for all). Approximately 100 min after the subjects went to sleep an additional blood flow rate increment (mean 56%) and a simultaneous significant decrease in mean arterial blood pressure (P less than 0.001) were observed. The duration of this hyperemic phase was 116 min. A highly significant reduction of the subcutaneous vascular resistance (50%) was demonstrated during the hyperemic blood flow rate phase compared with the surrounding phases (P less than 0.0001). The synchronism of the nocturnal subcutaneous hyperemia and the decrease in systemic mean arterial blood pressure point to a common, possibly central nervous or humoral, eliciting mechanism.

Hemodynamics in awake rabbits during hyperbaric helium-oxygen exposure

1980 ◽  
Vol 48 (2) ◽  
pp. 281-283 ◽  
Author(s):  
L. E. Boerboom ◽  
J. N. Boelkins
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cardiovascular System ◽  
Systemic Vascular Resistance ◽  
Elevated Pressure ◽  
Inert Gases ◽  
Gas Mixture ◽  
Organ Blood Flow

Although man is being exposed to hyperbaric environments more frequently, the effects of these environments and the inert gases used are not clearly defined. We therefore designed an experiment to examine both the effects of helium and elevated pressure on the cardiovascular system in conscious rabbits exposed to normoxic levels of a helium-oxygen (He-O2) gas mixture at 1 and 11 atmospheres absolute (ATA) for 2 h. Variables studied included heart rate, blood pressure, cardiac output, systemic vascular resistance, organ blood flow, and resistance to flow. The only change observed was a decrease in heart rate from a control of 284 +/- 7 (mean +/- SE) to 246 +/- 12 beats/min after 2 h of breathing He-O2 at 1 ATA. We therefore conclude that the cardiovascular system is not adversely affected by helium or elevated pressure as used in this experiment.

Influence of circulating NE and Epi on adipose tissue vascular resistance and lipolysis in humans

1983 ◽  
Vol 245 (3) ◽  
pp. H447-H452 ◽  
Author(s):  
P. Hjemdahl ◽  
B. Linde
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Vascular Resistance ◽  
Plasma Insulin ◽  
Human Adipose Tissue ◽  
Venous Occlusion ◽  
Tissue Blood Flow ◽  
Adipose Tissue Blood Flow ◽  
Arterial Plasma ◽  
Subcutaneous Adipose

The effects of circulating norepinephrine (NE) and epinephrine (Epi) on vascular resistance in subcutaneous adipose tissue and the calf as well as on plasma glycerol, an indicator of lipolysis, were studied in healthy volunteers. Adipose tissue blood flow was determined by the local clearance of 99mTcO-4 or 133Xe. The two isotopes gave similar results. Calf blood flow was determined by venous occlusion plethysmography. Intravenous infusion of NE caused increases in systolic and diastolic blood pressures, adipose tissue and calf vascular resistances, and plasma glycerol and a decrease in plasma insulin and heart rate, all of which were significant when arterial plasma NE was elevated from 1.17 +/- 0.14 to 8.38 +/- 0.30 nM (n = 16). Epi reduced diastolic and mean arterial pressures and adipose tissue and calf vascular resistances and increased plasma glycerol without affecting systolic blood pressure or plasma insulin. An increase of arterial plasma Epi from 0.20 +/- 0.03 to 1.15 +/- 0.05 nM (n = 6) was sufficient to induce vasodilatation in adipose tissue and lipolysis. Human adipose tissue differs from canine adipose tissue inasmuch as Epi causes vasodilatation in humans (present results) but vasoconstriction in the dog (previous results), presumably due to a predominance of vascular beta 2-adrenoceptors in human and beta 1-adrenoceptors in canine adipose tissue. Furthermore, Epi is a considerably more potent lipolytic hormone than NE in humans but not in the dog. Our results indicate that both NE and Epi may influence human adipose tissue blood flow and lipolysis as circulating hormones.

scholarly journals Effects of meal ingestion on blood pressure and regional hemodynamic responses after exercise

2016 ◽  
Vol 120 (11) ◽  
pp. 1343-1348 ◽  
Author(s):  
Masako Yamaoka Endo ◽  
Chizuko Fujihara ◽  
Akira Miura ◽  
Hideaki Kashima ◽  
Yoshiyuki Fukuba
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Young Male ◽  
Random Order ◽  
Carbohydrate Ingestion ◽  
Liquid Meal ◽  
Severe Hypotension ◽  
Meal Ingestion

This study investigated the combined effects of consuming a meal during postexercise hypotension (PEH) on hemodynamics. Nine healthy young male subjects performed each of three trials in random order: 1) cycling at 50% of heart rate reserve for 60 min, 2) oral ingestion of a carbohydrate liquid meal (75 g glucose), or 3) carbohydrate ingestion at 40 min after cycling exercise. Blood pressure, heart rate, cardiac output, and blood flow in the superior mesenteric (SMA), brachial, and popliteal arteries were measured continuously before and after each trial. Regional vascular conductance (VC) was calculated as blood flow/mean arterial pressure. Blood pressure decreased relative to baseline values ( P < 0.05) after exercise cessation. Blood flow and VC in the calf and arm increased after exercise, whereas blood flow and VC in the SMA did not. Blood pressure did not change after meal ingestion; however, blood flow and VC significantly decreased in the brachial and popliteal arteries and increased in the SMA for 120 min after the meal ( P < 0.05). When the meal was ingested during PEH, blood pressure decreased below PEH levels and remained decreased for 40 min before returning to postexercise levels. The sustained increase in blood flow and VC in the limbs after exercise was reduced to baseline resting levels immediately after the meal, postprandial cardiac output was unchanged by the increased blood flow in the SMA, and total VC and SMA VC increased. Healthy young subjects can suppress severe hypotension by vasoconstriction of the limbs even when carbohydrate is ingested during PEH.

Cardiovascular system

2011 ◽  
pp. 443-462
Author(s):  
Dr Mark Harrison
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cardiovascular System ◽  
Cardiac Cycle ◽  
Peripheral Circulation ◽  
Pharmacological Manipulation ◽  
System P

2.1 Control of blood pressure and heart rate, 445 2.2 Control of heart rate, 446 2.3 Cardiac output (CO), 447 2.4 Measurement of cardiac output (CO), 450 2.5 Blood flow peripherally, 451 2.6 The cardiac cycle, 454 2.7 ECG, 458 2.8 Pharmacological manipulation of the heart and peripheral circulation, ...

The Haemodynamic Effects of Metabolic Acidosis in the Rat

1976 ◽  
Vol 50 (3) ◽  
pp. 177-184 ◽  
Author(s):  
J. Yudkin ◽  
R. D. Cohen ◽  
Barbara Slack
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Metabolic Acidosis ◽  
Renal Blood Flow ◽  
Hepatic Blood Flow ◽  
Conscious Rats ◽  
Blood Ph ◽  
Significant Difference

1. The effect of metabolic acidosis of 4–6 h duration on cardiac output, blood pressure, heart rate, and hepatic and renal blood flow has been studied in the rat. 2. In anaesthetized rats, blood pressure and heart rate fell linearly with blood pH in both sham-operated and nephrectomized rats. There was no significant difference between the two groups in the effect of acidosis on either variable. 3. Cardiac output showed a significant fall with increasing acidosis in the conscious rat. 4. Estimated hepatic blood flow in conscious rats showed a significant positive correlation with blood pH in both sham-operated and nephrectomized animals. There was no significant difference in estimated hepatic blood flow between the two groups of animals at any blood pH. 5. In conscious rats, increasing acidosis caused a progressive decrease in estimated renal blood flow. 6. It is concluded that the increase in the previously described apparent renal contribution to lactate removal in the acidotic rat cannot be explained by any circulatory effect mediated by the kidney. The possible relevance of the findings to lactate homeostasis is discussed.

Regional distribution of blood flow during diving in the duck (Anas platyrhynchos)

1979 ◽  
Vol 57 (5) ◽  
pp. 995-1002 ◽  
Author(s):  
David R. Jones ◽  
Robert M. Bryan Jr. ◽  
Nigel H. West ◽  
Raymond H. Lord ◽  
Brenda Clark
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Mean Arterial Blood Pressure ◽  
Total Peripheral Resistance ◽  
Regional Distribution ◽  
Peripheral Resistance ◽  
Tissue Blood Flow ◽  
Arterial Blood ◽  
The Brain

The regional distribution of blood flow, both before and during forced diving, was studied in the duck using radioactively labelled microspheres. Cardiac output fell from 227 ± 30 to 95 ± 16 mL kg−1 min−1 after 20–72 s of submergence and to 59 ± 18 mL kg−1 min−1 after 144–250 s of submergence. Mean arterial blood pressure did not change significantly as total peripheral resistance increased by four times during prolonged diving. Before diving the highest proportion of cardiac output went to the heart (2.6 ± 0.5%, n = 9) and kidneys (2.7 ± 0.5%, n = 9), with the brain receiving less than 1%. The share of cardiac output going to the brain and heart increased spectacularly during prolonged dives to 10.5 ± 3% (n = 5) and 15.9 ± 3.8% (n = 5), respectively, while that to the kidney fell to 0.4 ± 0.26% (n = 3). Since cardiac output declined during diving, tissue blood flow (millilitres per gram per minute) to the heart was unchanged although in the case of the brain it increased 2.35 times after 20–75 s of submergence and 8.5 times after 140–250 s of submergence. Spleen blood flow, the highest of any tissue predive (5.6 ± 1.3 mL g−1 min−1, n = 4), was insignificant during diving while adrenal flow increased markedly, in one animal reaching 7.09 mL g−1 min−1. The present results amplify general conclusions from previous research on regional distribution of blood flow in diving homeotherms, showing that, although both heart and brain receive a significant increase in the proportionate share of cardiac output during diving only the brain receives a significant increase in tissue blood flow, which increases as submergence is prolonged.

scholarly journals Blood flow distribution in submerged and surface-swimming ducks

1992 ◽  
Vol 166 (1) ◽  
pp. 285-296
Author(s):  
R. Stephenson ◽  
D. R. Jones
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Water Surface ◽  
Imaging Technique ◽  
Flow Distribution ◽  
Tissue Blood Flow ◽  
Blood Flow Distribution ◽  
Radiological Imaging ◽  
Aythya Americana

Observations that the response of the avian heart rate to submergence varies under different circumstances have led to speculation about variability of blood flow distribution during voluntary dives. We used a radiological imaging technique to examine the patterns of circulating blood flow in captive redhead ducks (Aythya americana) during rest, swimming, escape dives, forced dives and trapped escape dives and have shown that blood flow distribution in escape dives was the same as that in ducks swimming at the water surface. The response during trapped escape dives, however, was highly variable. Blood pressure was unchanged from the resting value during all activities. Predictions made about blood flow distribution during unrestrained dives on the basis of heart rate and other indirect data were confirmed in this study. However, the trapped escape dive responses indicated that heart rate alone is not always a reliable indicator of tissue blood flow in exercising ducks.

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