EFFECT OF ENDRIN ON VENOUS RETURN AND CATECHOLAMINE RELEASE IN THE DOG

1966 ◽  
Vol 44 (1) ◽  
pp. 59-67 ◽  
Author(s):  
D. A. Reins ◽  
J. A. Rieger Jr. ◽  
W. B. Stavinoha ◽  
L. B. Hinshaw
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Adrenal Glands ◽  
Venous Return ◽  
Lethal Dose ◽  
Peripheral Resistance ◽  
Primary Source ◽  
Arterial Blood ◽  
Total Body ◽  
The Relationship

Previous reports have shown that dogs treated with the insecticide endrin develop marked changes in blood pressure and heart rate accompanied by convulsions terminating in death. The present study was designed to determine the relationship between venous return (cardiac output), total peripheral vascular resistance, and hypertension seen in succinylcholine-treated dogs after a lethal dose of endrin. Experiments were performed on "intact" (viscera intact) and eviscerated dogs under conditions of total body perfusion. Results indicate that the rise in systemic arterial blood pressure depends primarily on increased cardiac output due to an elevated venous return. Total peripheral resistance does not change significantly in either group of animals. The abdominal viscera were the primary source of the increase in venous return after endrin. Adrenal glands were partially depleted of adrenaline, and increased levels of adrenaline and noradrenaline found in blood plasma may explain the marked alterations in systemic hemodynamics.

Role of vasopressin in acutely altered baroreflex sensitivity during hemorrhage in rats

1991 ◽  
Vol 261 (3) ◽  
pp. R677-R685 ◽  
Author(s):  
B. L. Brizzee ◽  
R. D. Russ ◽  
B. R. Walker
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Blood Loss ◽  
Baroreflex Sensitivity ◽  
Peripheral Resistance ◽  
Conscious Rat ◽  
Arterial Blood ◽  
Arterial Hemorrhage ◽  
Moderate Elevation

Experiments were performed to examine the potential role of circulating arginine vasopressin (AVP) on baroreflex sensitivity during hypotensive and nonhypotensive hemorrhage in the conscious rat. Animals were chronically instrumented for measurement of cardiac output, blood pressure, and heart rate (HR). Three potential stimuli for release of AVP were utilized: 1) rapid 20% arterial hemorrhage that resulted in hypotension, 2) nonhypovolemic hypotension induced by intravenous infusion of nitroprusside, and 3) nonhypotensive hemorrhage (rapid 10% arterial blood withdrawal). Hypotensive hemorrhage was associated with significant reductions in blood pressure, cardiac output, HR, and calculated total peripheral resistance, an increase in baroreflex (BRR) bradycardia in response to pressor infusions of phenylephrine, and a moderate elevation in circulating AVP. Prior intravenous administration of a specific V1-vasopressinergic antagonist augmented the hypotensive response to hemorrhage; however, neither V1- nor V2-blockade affected hemorrhage-induced augmentation of the BRR. Inducement of hypotension by infusion of nitroprusside did not alter subsequent BRR sensitivity. Finally, nonhypotensive hemorrhage was associated with an increase in resting HR and augmented BRR sensitivity. However, in contrast to hypotensive hemorrhage, either V1- or V2-antagonism attenuated the increase in BRR sensitivity seen with 10% hemorrhage. These data suggest that, although AVP may play a role in blood pressure maintenance via its direct vasoconstrictor actions during hypotensive hemorrhage, the observed augmentation of BRR sensitivity associated with severe blood loss is not attributable to a vasopressinergic mechanism activated by circulating AVP. However, blood-borne AVP may contribute to BRR sensitivity alterations in response to mild blood loss.

Effect of sympathetic blockade on diurnal variation of hemodynamic patterns

1989 ◽  
Vol 256 (3) ◽  
pp. R778-R785 ◽  
Author(s):  
M. I. Talan ◽  
B. T. Engel
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Base Line ◽  
Sympathetic Blockade ◽  
Selective Blockade ◽  
Arterial Blood

Heart rate, stroke volume, and intra-arterial blood pressure were monitored continuously in each of four monkeys, 18 consecutive h/day for several weeks. The mean heart rate, stroke volume, cardiac output, systolic and diastolic blood pressure, and total peripheral resistance were calculated for each minute and reduced to hourly means. After base-line data were collected for approximately 20 days, observation was continued for equal periods of time under conditions of alpha-sympathetic blockade, beta-sympathetic blockade, and double sympathetic blockade. This was achieved by intra-arterial infusion of prazosin, atenolol, or a combination of both in concentration sufficient for at least 75% reduction of response to injection of agonists. The results confirmed previous findings of a diurnal pattern characterized by a fall in cardiac output and a rise in total peripheral resistance throughout the night. This pattern was not eliminated by selective blockade, of alpha- or beta-sympathetic receptors or by double sympathetic blockade; in fact, it was exacerbated by sympathetic blockade, indicating that the sympathetic nervous system attenuates these events. Because these findings indicate that blood volume redistribution is probably not the mechanism mediating the observed effects, we have hypothesized that a diurnal loss in plasma volume may mediate the fall in cardiac output and that the rise in total peripheral resistance reflects a homeostatic regulation of arterial pressure.

Carotid baroreceptor control of liver and spleen volume in cats

1991 ◽  
Vol 260 (1) ◽  
pp. H254-H259
Author(s):  
R. Maass-Moreno ◽  
C. F. Rothe
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Arterial Blood Pressure ◽  
Total Peripheral Resistance ◽  
Venous Pressure ◽  
Peripheral Resistance ◽  
Normal Brain ◽  
Spleen Volume ◽  
Arterial Blood

We tested the hypothesis that the blood volumes of the spleen and liver of cats are reflexly controlled by the carotid sinus (CS) baroreceptors. In pentobarbital-anesthetized cats the CS area was isolated and perfused so that intracarotid pressure (Pcs) could be controlled while maintaining a normal brain blood perfusion. The volume changes of the liver and spleen were estimated by measuring their thickness using ultrasonic techniques. Cardiac output, systemic arterial blood pressure (Psa), central venous pressure, central blood volume, total peripheral resistance, and heart rate were also measured. In vagotomized cats, increasing Pcs by 100 mmHg caused a significant reduction in Psa (-67.8%), cardiac output (-26.6%), total peripheral resistance (-49.5%), and heart rate (-15%) and significantly increased spleen volume (9.7%, corresponding to a 2.1 +/- 0.5 mm increase in thickness). The liver volume decreased, but only by 1.6% (0.6 +/- 0.2 mm decrease in thickness), a change opposite that observed in the spleen. The changes in cardiovascular variables and in spleen volume suggest that the animals had functioning reflexes. These results indicate that in pentobarbital-anesthetized cats the carotid baroreceptors affect the volume of the spleen but not the liver and suggest that, although the spleen has an active role in the control of arterial blood pressure in the cat, the liver does not.

Circulatory effects of acute or chronic endotoxemia in rats

1981 ◽  
Vol 59 (2) ◽  
pp. 204-208 ◽  
Author(s):  
R. Keeler ◽  
Anamaria Barrientos ◽  
K. Lee
Keyword(s):  
Escherichia Coli ◽  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Gastrointestinal Tract ◽  
Peripheral Resistance ◽  
Circulatory Effects ◽  
Arterial Blood ◽  
Flow Changes ◽  
Fractional Distribution

A study was made of the effects of acute (4 h) or chronic (4 days) infusion of Escherichia coli endotoxin on cardiovascular function in rats. Rats with acute endotoxemia had a reduced cardiac output but maintained their arterial blood pressure. Fractional distribution of the cardiac output was increased to the liver and reduced to the gastrointestinal tract and skin. No changes in fractional distribution to the kidneys, lungs, or heart were observed although absolute blood flow to these areas was reduced.Rats with chronic endotoxemia had a reduced cardiac output and hypotension with no change in peripheral resistance. Other changes resembled those seen in acute endotoxemia apart from a low renal fraction of the cardiac output. Calculation and interpretation of blood flow changes in these animals was difficult because of a large fall in hematocrit and changes in organ weight.

Cardiac Output by the Dye Dilution Technique Under Thiopental Sodium-Oxygen and Ether Anesthesia

1956 ◽  
Vol 186 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Esther M. Greisheimer ◽  
Dorothy W. Ellis ◽  
George Stewart ◽  
Lydia Makarenko ◽  
Nadia Oleksyshyn ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Arterial Blood Pressure ◽  
Total Peripheral Resistance ◽  
Peripheral Resistance ◽  
Stroke Index ◽  
Ether Anesthesia ◽  
Dye Dilution ◽  
Arterial Blood ◽  
Thiopental Sodium

One hundred-twenty determinations of cardiac output by the dye dilution technic utilizing the cuvette oximeter were made on 20 dogs. Of these, 60 were done under thiopental sodium-oxygen analgesia and 60 were done after supplementing with ether. Arterial blood pressure was recorded by strain gauge. Electrocardiograms were taken periodically. Concentrations of thiopental and ether in arterial blood were determined. Cardiac output began to increase under thiopental analgesia and continued to increase when ether was administered. Arterial blood pressure and heart rate decreased slightly when ether was administered. Stroke index increased when ether was administered. Total peripheral resistance decreased markedly under thiopental analgesia, and continued to decrease when ether was administered. When compared with an earlier study in which cyclopropane was used as the supplementing agent, it was found that cyclopropane and ether exert opposite effects on cardiac output and peripheral resistance despite the fact that the effect on arterial blood pressure is similar under the two agents. Increase in cardiac output was found to be parallel with decrease in total peripheral resistance in this study. Amount of dye injected did not influence cardiac output. Under the conditions of this study, cardiac output was in no way dependent on the concentration of thiopental in the blood nor on the amount injected. Level of ether in the blood did not show much effect, if any, on cardiac output. It is probable that the changes observed in this study are comparable with those which obtain clinically when thiopental-oxygen analgesia is supplemented with ether. Systolic blood pressure is not an infallible guide to other cardiovascular functions since it may remain fairly steady while cardiac output and peripheral resistance undergo marked changes under anesthesia.

scholarly journals Continuous cardiac output monitoring in humans by invasive and noninvasive peripheral blood pressure waveform analysis

2006 ◽  
Vol 101 (2) ◽  
pp. 598-608 ◽  
Author(s):  
Zhenwei Lu ◽  
Ramakrishna Mukkamala
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Waveform Analysis ◽  
Cardiac Output Monitoring ◽  
Time Interval ◽  
Data Sets ◽  
Data Set ◽  
Arterial Blood ◽  
Output Monitoring

We present an evaluation of a novel technique for continuous (i.e., automatic) monitoring of relative cardiac output (CO) changes by long time interval analysis of a peripheral arterial blood pressure (ABP) waveform in humans. We specifically tested the mathematical analysis technique based on existing invasive and noninvasive hemodynamic data sets. With the former data set, we compared the application of the technique to peripheral ABP waveforms obtained via radial artery catheterization with simultaneous thermodilution CO measurements in 15 intensive care unit patients in which CO was changing because of disease progression and therapy. With the latter data set, we compared the application of the technique to noninvasive peripheral ABP waveforms obtained via a finger-cuff photoplethysmography system with simultaneous Doppler ultrasound CO measurements made by an expert in 10 healthy subjects during pharmacological and postural interventions. We report an overall CO root-mean-squared normalized error of 15.3% with respect to the invasive hemodynamic data set and 15.1% with respect to the noninvasive hemodynamic data set. Moreover, the CO errors from the invasive and noninvasive hemodynamic data sets were only mildly correlated with mean ABP (ρ = 0.41, 0.37) and even less correlated with CO (ρ = −0.14, −0.17), heart rate (ρ = 0.04, 0.19), total peripheral resistance (ρ = 0.38, 0.10), CO changes (ρ = −0.26, −0.20), and absolute CO changes (ρ = 0.03, 0.38). With further development and successful prospective testing, the technique may potentially be employed for continuous hemodynamic monitoring in the acute setting such as critical care and emergency care.

scholarly journals Dynamics of Concatenation between Cardiac Output and Indices of Arterial Blood Presure during Graded Exercise Stress in Endurance Cohort

2018 ◽  
Vol 1 (88) ◽  
Author(s):  
Vilma Papievienė ◽  
Eugenijus Trinkūnas ◽  
Alfonsas Buliuolis ◽  
Albinas Grūnovas ◽  
Jonas Poderys
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Vascular Resistance ◽  
Matrix Theory ◽  
Blood Pressure Reduction ◽  
Peripheral Resistance ◽  
Exercise Stress ◽  
Bicycle Ergometry ◽  
Linear Type ◽  
Arterial Blood

Research background and hypothesis. Potential mechanisms through which muscle perfusion is altered during prolonged exercise are not fully understood. The methods applied in the  analysis of human data are very important  because  many crucial variables are not directly measureble or even identifiable.Research aim  was to  find out the peculiarities in concatenation between  central and peripheral cardiovascular changes under conditions of increasing fatigue.Research methods. Well-trained endurance runners underwent a 50 W increase in workload (bicycle ergometry) every 6 minutes and they exercised until inability to continue the task. Dynamics of concatenation between cardiac output and systolic arterial blood pressure (ABP), diastolic ABP and total peripheral resistance were assessed using a method based on matrix theory proposed by Lithuanian scientists.Research results. The increase of cardiac output during exercising has the same tendency of stepwise increase of workload, but changes of systolic and diastolic ABP with accumulation of fatigue could be characterized as linear type dependent with the time of exercising. The concatenation between the changes in cardiac performance and behaviour of peripheral vasculature increased at onset of exercising and the decrease or loss of the concatenation led up to inability to continue exercising.Discussion and conclusions. The importance of peripheral factors, i. e. decrease of diastolic blood pressure, reduction  of  total  peripheral  vascular  resistance  plays  an  increasingly  significant  role  for  cardiac  output  during continuous exercising. The concatenations between the changes of these indices and cardiac output increase and in the case of high-grade fatigue concatenations begin to decline.Keywords: cardiac output, periferal vascular resistance, concatenation.

Cardiac output and its distribution during diving in the rat

1975 ◽  
Vol 228 (3) ◽  
pp. 733-737 ◽  
Author(s):  
YC Lin ◽  
DG Baker
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Diving Response ◽  
Fourfold Increase ◽  
Arterial Blood ◽  
Cardiovascular Model ◽  
Blood Flow Reduction

The diving response was produced by submerging the head of the unanesthetized rat for 60 s, while it was confined in a mesh-wired cone. Heart rate and cardiac output decreased by 73% and 74% from the predive values, respectively, indicating insignificant change in stroke volume. Central systemic arterial blood pressure rose by 22% during diving and a fourfold increase in total peripheral resistance was observed. Blood flow to the coronary, cerebral, and bronchial circulations remained unchanged while a 95% reduction in the intestine and the spleen, a 97% reduction in the kidney, and greater than 99% reduction in the tail and skin were observed during diving. The blood flow reduction from predive values ranged from 50% for liver and skeletal muscle to 75% for the adrenals and 65% for the diaphragm. The redistribution of the drastically reduced cardiac output during head immersion in the rat is similar to that reported for diving mammals. It is suggested that the rat may serve as a useful cardiovascular model for further studies of the diving response in mammals.

Effects of vasopressin on arterial blood pressure and cardiac output in male and female rats

1991 ◽  
Vol 261 (5) ◽  
pp. R1118-R1125 ◽  
Author(s):  
K. Toba ◽  
J. T. Crofton ◽  
M. Inoue ◽  
L. Share
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Pressor Response ◽  
Peripheral Resistance ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Arterial Blood ◽  
Male And Female Rats ◽  
Cycle Dependent

This study was performed to investigate further the mechanisms underlying the sexual dimorphism of the pressor responses to vasopressin. We have confirmed our earlier findings that the pressor response to graded infusions of vasopressin in conscious unrestrained male rats is similar to that in estrous females and greater than in diestrus, proestrus, and metestrus. This difference was due primarily to greater increases in total peripheral resistance (TPR) in males and estrous females, since there were no sex- or cycle-related differences in the vasopressin-induced reductions in cardiac output. Gonadectomy was without effect in males but, in females, increased blood pressure responses to vasopressin to levels found in males. Chronic treatment of ovariectomized rats with estradiol reduced pressor responsiveness to vasopressin; treatment with progesterone was without effect. These differences were also due to differences in TPR. It is concluded that the sex- and cycle-dependent differences in vasopressin-induced increases in blood pressure are due largely to attenuation of increases in TPR by estrogen.

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.

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