Very small microspheres are useful for the determination of cardiac output but not organ blood flow in conscious rabbits

1981 ◽  
Vol 37 (4) ◽  
pp. 438-439 ◽  
Author(s):  
R. P. Hof ◽  
A. Hof
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Organ Blood Flow ◽  
Conscious Rabbits

Dose-Dependent Effects of Meclofenamate on Peripheral Vasculature of Conscious Rabbits

1983 ◽  
Vol 64 (5) ◽  
pp. 471-474 ◽  
Author(s):  
R. A. Banks ◽  
L. J. Beilin ◽  
J. Soltys
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Organ Blood Flow ◽  
Hepatic Circulation ◽  
Peripheral Vasculature ◽  
Conscious Rabbits ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
The Brain ◽  
Intravenous Sodium

1. Changes in systemic haemodynamics and organ blood flow were measured in conscious rabbits after various doses of intravenous sodium meclofenamate, an inhibitor of prostaglandin cyclo-oxygenase. 2. Meclofenamate had no effect on arterial pressure or cardiac output but caused a dose-dependent fall in renal blood flow. 3. Meclofenamate also reduced adrenal perfusion but, in contrast, caused a dose-dependent increase in blood flow to the brain, bronchial and hepatic circulation and to the testis. No effect was demonstrated on other organs studied. 4. The effect on the cerebral circulation was observed at the lowest dose of meclofenamate (0.75 mg/kg). Higher total doses were necessary for an effect on the renal and bronchial (3 mg/kg) and testicular and hepatic arteries (6 mg/kg). 5. The results suggest a variety of local vasomotor influences of renal and non-renal prostaglandins in conscious rabbits.

scholarly journals Pentoxifylline prevents the transition from the hyperdynamic to hypodynamic response during sepsis

1999 ◽  
Vol 277 (3) ◽  
pp. H1036-H1044 ◽  
Author(s):  
Shaolong Yang ◽  
Mian Zhou ◽  
Douglas J. Koo ◽  
Irshad H. Chaudry ◽  
Ping Wang
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cardiovascular Response ◽  
Cecal Ligation ◽  
Organ Blood Flow ◽  
Adult Rats ◽  
Male Adult ◽  
Morphological Alterations ◽  
Beneficial Effects ◽  
Renal Oxygen

The cardiovascular response to sepsis includes an early, hyperdynamic phase followed by a late, hypodynamic phase. Although administration of pentoxifylline (PTX) produces beneficial effects in sepsis, it remains unknown whether this agent prevents the transition from the hyperdynamic to the hypodynamic response during the progression of sepsis. To study this, male adult rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). At 1 h after CLP, PTX (50 mg/kg body wt) or vehicle was infused intravenously over 30 min. At 20 h after CLP (i.e., the late stage of sepsis), cardiac output and organ blood flow were measured by radioactive microspheres. Systemic and regional (i.e., hepatic, intestinal, and renal) oxygen delivery (Do 2) and oxygen consumption (V˙o 2) were determined. Moreover, plasma levels of lactate and alanine aminotransferase (ALT) were measured, and histological examinations were performed. In additional animals, the necrotic cecum was excised at 20 h after CLP, and mortality was monitored for 10 days thereafter. The results indicate that cardiac output, organ blood flow, and systemic and regional Do 2decreased by 36–65% ( P < 0.05) at 20 h after CLP. Administration of PTX early after the onset of sepsis, however, prevented reduction in measured hemodynamic parameters and increased systemic and regional Do 2 andV˙o 2 by 50–264% ( P < 0.05). The elevated levels of lactate (by 173%, P < 0.05) and ALT (by 718%, P < 0.05), as well as the morphological alterations in the liver, small intestine, and kidneys during sepsis were attenuated by PTX treatment. In addition, PTX treatment decreased the mortality rate from 50 to 0% ( P < 0.05) after CLP and cecal excision. Because PTX prevents the occurrence of hypodynamic sepsis, this agent appears to be a useful adjunct for maintaining hemodynamic stability and preventing lethality from sepsis.

Abstract 67: Vasopressin impairs Brain, Heart and Kidney Perfusion in Acute Heart Failure

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Stig Müller ◽  
Ole-Jakob How ◽  
Stig E Hermansen ◽  
Truls Myrmel
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Heart Function ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Arterial Blood Flow ◽  
Organ Blood Flow ◽  
Arterial Blood ◽  
Time Flow ◽  
The Brain

Arginin Vasopressin (AVP) is increasingly used to restore mean arterial pressure (MAP) in various circulatory shock states including cardiogenic shock. This is potentially deleterious since AVP is also known to reduce cardiac output by increasing vascular resistance. Aim: We hypothesized that restoring MAP by AVP improves vital organ blood flow in experimental acute cardiac failure. Methods: Cardiac output (CO) and arterial blood flow to the brain, heart, kidney and liver were measured in nine pigs by transit-time flow probes. Heart function and contractility were measured using left ventricular Pressure-Volume catheters. Catheters in central arteries and veins were used for pressure recordings and blood sampling. Left ventricular dysfunction was induced by intermittent coronary occlusions, inducing an 18 % reduction in cardiac output and a drop in MAP from 87 ± 3 to 67 ± 4 mmHg. Results: A low-dose therapeutic infusion of AVP (0.005 u/kg/min) restored MAP but further impaired systemic perfusion (CO and blood flow to the brain, heart and kidney reduced by 29, 18, 23 and 34 %, respectively). The reduced blood flow was due to a 2.0, 2.2, 1.9 and 2.1 fold increase in systemic, brain, heart and kidney specific vascular resistances, respectively. Contractility remained unaffected by AVP. The hypoperfusion induced by AVP was most likely responsible for observed elevated plasma lactate levels and an increased systemic oxygen extraction. Oxygen saturation in blood drawn from the great cardiac vein fell from 31 ± 1 to 22 ± 3 % dropping as low as 10 % in one pig. Finally, these effects were reversed forty minutes after weaning the pigs form the drug. Conclusion: The pronounced reduction in coronary blood flow point to a potentially deleterious effect in postoperative cardiac surgical patients and in patients with coronary heart disease. Also, this is the first study to report a reduced cerebral perfusion by AVP.

Effect of Dietary Restriction during Lactation on Cardiac Output, Organ Blood Flow and Organ Weights of Rats

1987 ◽  
Vol 117 (8) ◽  
pp. 1469-1474 ◽  
Author(s):  
Tammy M. Sakanashi ◽  
Heather E. Brigham ◽  
Kathleen M. Rasmussen
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Dietary Restriction ◽  
Organ Blood Flow ◽  
Organ Weights

Effect of serotonin on cardiac output and organ blood flow of rats

1963 ◽  
Vol 204 (2) ◽  
pp. 301-303 ◽  
Author(s):  
L. Takács ◽  
V. Vajda
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Intravenous Infusion ◽  
Organ Distribution ◽  
Organ Blood Flow ◽  
Cutaneous Blood Flow ◽  
Pulmonary Parenchyma ◽  
Cutaneous Blood

The effects of intraperitoneal and intravenous administration of serotonin on cardiac output, blood pressure, and organ distribution of blood flow (Rb86) were studied in the rat. Fifteen to thirty minutes after intraperitoneal injection (10 mg/kg) cardiac output was unchanged, while blood pressure was significantly reduced. Increase in blood flow was noted in the myocardium, pulmonary parenchyma and "carcass" (skeletal muscle, bone, CNS), with decrease in the kidney and the skin. Splanchnic blood flow was unchanged. Conversely, intravenous infusion of serotonin produced an increase of cardiac output, blood pressure, and cutaneous blood flow.

Cardiac output and organ blood flow in warm- and cold-acclimated rats exposed to cold

1968 ◽  
Vol 46 (4) ◽  
pp. 653-659 ◽  
Author(s):  
L. Jansky ◽  
J. S. Hart
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Skeletal Muscles ◽  
Organ Blood Flow ◽  
Internal Organs ◽  
Exposure To Cold ◽  
Brown Adipose ◽  
Production Increase ◽  
Distribution Of Cardiac Output ◽  
Fractional Distribution

Cold acclimation increased the cardiac output of unanesthetized rats when measured at 30 °C. After exposure to 9 °C for 70 min cardiac output further increased by 46% in both warm- and cold-acclimated rats. From the changes in the fractional distribution of cardiac output after cold exposure it was shown that the blood flow increased significantly in muscular organs (heart, diaphragm, skeletal muscles) and in the adrenals of warm-acclimated rats. In cold-acclimated rats the blood flow to the brown and white adipose tissues, pancreas, kidney, intestine, liver, and other internal organs was also increased in a cold environment, and accounted for 65% of the increase in blood flow during exposure to cold compared with only 36% in warm-acclimated rats. It is estimated that the extramuscular thermogenesis can account for a greater proportion of the total nonshivering thermogenesis in cold-acclimated rats. The contribution of brown adipose tissue is estimated not to exceed about 6% of the total heat production increase in cold-acclimated rats during exposure to cold.

The Effects of Meclofenamate, Captopril and Phentolamine on Organ Blood Flow in the Conscious Rabbit

1981 ◽  
Vol 61 (1) ◽  
pp. 97-105 ◽  
Author(s):  
R. A. Banks ◽  
L. J. Beilin
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Hepatic Artery ◽  
Peripheral Resistance ◽  
Prostaglandin Synthesis ◽  
Organ Blood Flow ◽  
Inhibit Prostaglandin Synthesis ◽  
Conscious Rabbits ◽  
Artery Flow ◽  
Intravenous Sodium

1. Systemic and regional vascular changes were measured in conscious rabbits after intravenous sodium meclofenamate, captopril and phentolamine. These drugs were used respectively to inhibit prostaglandin synthesis and angiotensin-converting enzyme, and to block α-adrenoceptors. 2. Meclofenamate reduced renal and adrenal blood flow by 11 and 28% respectively, and doubled hepatic artery flow. The effect on renal and adrenal flow persisted in the presence of phentolamine. 3. Captopril decreased estimated peripheral resistance and increased cardiac output without changing arterial pressure. Kidney and adrenal flow increased by 70 and 21% respectively. 4. Phentolamine reduced arterial pressure and doubled flow to skeletal muscle and increased hepatic artery flow to the liver. 5. Splenic blood flow was unaffected by meclofenamate, captopril or phentolamine alone. Meclofenamate given after captopril caused a halving of splenic flow and a rise in arterial pressure; these effects were prevented by phentolamine. 6. The results point to a continuing effect of prostaglandin synthesis in maintaining blood flow to the kidney and adrenal gland independent of α-adrenoceptor activation in resting conscious rabbits. An important modulating effect of prostaglandins on sympathetic vascular tone in the spleen is suggested.

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