Relationship between portal venous and hepatic arterial blood flows: spectrum of response

1990 ◽  
Vol 259 (6) ◽  
pp. G1010-G1018 ◽  
Author(s):  
T. Kawasaki ◽  
F. J. Carmichael ◽  
V. Saldivia ◽  
L. Roldan ◽  
H. Orrego
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
Portal Vein Ligation ◽  
Artery Ligation ◽  
Blood Flows ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Relationship ◽  
Group D

The relationship between portal tributary blood flow (PBF) and hepatic arterial blood flow (HAF) was studied in awake, unrestrained rats with the radiolabeled microsphere technique. Six distinct patterns of response emerged. In group A (PBF+, HAF 0), ethanol, acetate, glucagon, prostacyclin, and a mixed diet increased PBF without a change in HAF; in group B (PBF+, HAF+), adenosine and histamine increased both PBF and HAF; in group C (PBF 0, HAF+), isoflurane and triiodothyronine did not change PBF but increased HAF; and in group D (PBF-, HAF+), halothane and vasopressin decreased PBF and increased HAF. Acute partial portal vein ligation decreased PBF (56%) and increased HAF (436%). Hypoxia (7.5% O2) decreased PBF (28%) and increased HAF (110%). In group E (PBF+, HAF-), acute hepatic artery ligation increased PBF (35%) and reduced HAF (74%), while in group F (PBF-, HAF-), thyroidectomy reduced PBF and HAF (36 and 47%, respectively). All blood flow responses were accompanied by the expected changes in both portal tributary and hepatic arterial vascular resistances. The data suggest that the portal and hepatic arterial vascular territories have regulatory mechanisms that allow for independent changes.

Regional blood flow in the brain and spinal cord of hypothermic rats

1989 ◽  
Vol 257 (3) ◽  
pp. H785-H790
Author(s):  
T. Sakamoto ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Brain Stem ◽  
Regional Blood Flow ◽  
Experimental Conditions ◽  
Pentobarbital Sodium ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

Pulmonary blood flow, pressure and resistance following tetraethylammonium and aminophylline

1961 ◽  
Vol 200 (2) ◽  
pp. 287-291 ◽  
Author(s):  
M. Harasawa ◽  
S. Rodbard
Keyword(s):  
Blood Flow ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Arterial Blood Flow ◽  
Tetraethylammonium Chloride ◽  
Blood Flows ◽  
Arterial Blood ◽  
Pulmonary Arterial ◽  
Flow Pressure

The effects of tetraethylammonium chloride (TEAC) and aminophylline on the pulmonary vascular resistance were studied in thoracotomized dogs. Pulmonary arterial blood flow and pressure, and systemic blood pressure were measured simultaneously. Both drugs showed marked hypotensive effects on the systemic vessels. In every instance pulmonary arterial pressures and blood flows were reduced by TEAC given via the pulmonary artery and increased by aminophylline. However, the calculated pulmonary vascular resistance remained essentially unchanged in all experiments. These data challenge the concept that the pulmonary vessels respond to these drugs by active vasodilatation

scholarly journals The Effect of S. Pneumoniae Bacteremia on Cerebral Blood Flow Autoregulation in Rats

2007 ◽  
Vol 28 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Michael Pedersen ◽  
Christian T Brandt ◽  
Gitte M Knudsen ◽  
Christian Østergaard ◽  
Peter Skinhøj ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Lower Limit ◽  
Perfusion Pressure ◽  
Regression Line ◽  
Pneumococcal Bacteremia ◽  
Group A ◽  
Group B ◽  
Cerebral Vasodilation ◽  
Group D

In the present study, we studied the effect of bacteremia on cerebral blood flow (CBF) autoregulation in a rat model of pneumococcal bacteremia and meningitis. Anesthetized rats were divided into five groups (A to E) and inoculated with pneumococci intravenously and normal saline intracisternally (group A, N = 10); saline intravenously and pneumococci intracisternally (group B, N = 10); pneumococci intravenously and pneumococci intracisternally (group C, N = 5); saline intravenously, antipneumococcal antibody intravenously (to prevent bacteremia), and pneumococci intracisternally (group D, N = 10); or saline intravenously and saline intracisternally (group E, N = 10), respectively. Positive cultures occurred in the blood for all rats in groups A, B, and C, and in the cerebrospinal fluid for all rats in groups D and E. Twenty-four hours after inoculation, CBF was measured with laser-Doppler ultrasound during incremental reductions in cerebral perfusion pressure (CPP) by controlled hemorrhage. Autoregulation was preserved in all rats without meningitis (groups A and E) and was lost in 24 of 25 meningitis rats (groups B, C, and D) ( P <0.01). In group A, the lower limit was higher than that of group E ( P <0.05). The slope of the CBF/CPP regression line differed between the meningitis groups ( P < 0.001), being steeper for group B than groups C and D, with no difference between these two groups. The results suggest that pneumococcal bacteremia in rats triggers cerebral vasodilation, which right shifts the lower limit of, but does not entirely abolish, CBF autoregulation in the absence of meningitis, and which may further aggravate the vasoparalysis induced by concomitant pneumococcal meningitis.

Increase in hepatic blood flow during early sepsis is due to increased portal blood flow

1991 ◽  
Vol 261 (6) ◽  
pp. R1507-R1512 ◽  
Author(s):  
P. Wang ◽  
Z. F. Ba ◽  
I. H. Chaudry
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Hepatic Blood Flow ◽  
Portal Blood Flow ◽  
Portal Blood ◽  
Arterial Blood Flow ◽  
Blood Flows ◽  
Arterial Blood ◽  
Total Hepatic Blood Flow ◽  
Early Sepsis

Although hepatic blood flow increases significantly during early sepsis [as produced by cecal ligation and puncture (CLP)], it is not known whether this is due to the increase in portal or hepatic arterial blood flows. To study this, rats were subjected to CLP, after which they and sham-operated rats received either 3 or 6 ml normal saline/100 g body wt subcutaneously (i.e., all rats received crystalloid therapy). Blood flow in various organs was determined by using a radioactive microsphere technique at 5 and 20 h after CLP or sham operation. Portal blood flow was calculated as the sum of blood flows to the spleen, pancreas, gastrointestinal tract, and mesentery. Total hepatic blood flow was the sum of portal blood flow and hepatic arterial blood flow. A significant increase in portal blood flow and in total hepatic blood flow was observed at 5 h after CLP (i.e., early sepsis), and this was not altered by doubling the volume of crystalloid resuscitation after the induction of sepsis. In contrast, hepatic arterial blood flow during early sepsis was found to be similar to control; however, it was significantly reduced in late sepsis (i.e., 20 h after CLP). Cardiac output was significantly higher than the control in early sepsis. However, even in late sepsis, cardiac output and total hepatic blood flow were not significantly different from controls. These results indicate that the increased total hepatic blood flow during early hyperdynamic sepsis is solely due to the increased portal blood flow.

ON THE RELATIONSHIP BETWEEN TESTICULAR BLOOD FLOW AND SECRETION OF TESTOSTERONE IN ANESTHETIZED DOGS STIMULATED WITH HUMAN CHORIONIC GONADOTROPHIN

1964 ◽  
Vol 42 (5) ◽  
pp. 671-677 ◽  
Author(s):  
Kristen B. Eik-Nes
Keyword(s):  
Blood Flow ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Arterial Blood Flow ◽  
Constant Infusion ◽  
Left Testis ◽  
Arterial Blood ◽  
Constant Rate ◽  
Anesthetized Dogs ◽  
The Relationship

The concentration of testosterone has been measured in spermatic vein blood from the left testis in 25 anesthetized dogs, stimulated with human chorionic gonadotrophin and infused with arterial blood via the left spermatic artery at different rates. The secretion of testosterone varied with the rate at which arterial blood was infused and at a constant infusion rate of 3.81 ml/min, animals weighing from 19 to 23 kg produced testosterone at a constant rate over 90 minutes. Infusion rates lower than this decreased the secretion of testosterone, and if arterial blood was infused at a rate of 0.76 ml/min for the first 30 minutes of experimentation, the capacity of the infused testis to secrete testosterone in the ensuing 60 minutes was impaired even in animals given large doses of human chorionic gonadotrophin via the left spermatic artery. A relationship between the arterial blood flow to the testis and its ability to secrete testosterone under the influence of human chorionic gonadotrophin is thus established.

Spleen volume and blood flow response to repeated breath-hold apneas

2003 ◽  
Vol 95 (4) ◽  
pp. 1460-1466 ◽  
Author(s):  
Darija Baković ◽  
Zoran Valic ◽  
Davor Eterović ◽  
Ivica Vuković ◽  
Ante Obad ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cold Water ◽  
Splenic Vein ◽  
Arterial Blood Flow ◽  
Breath Hold ◽  
Spleen Volume ◽  
Blood Flows ◽  
Arterial Blood ◽  
Active Contraction ◽  
Spleen Contraction

The purpose of this study was 1) to answer whether the reduction in spleen size in breath-hold apnea is an active contraction or a passive collapse secondary to reduced splenic arterial blood flow and 2) to monitor the spleen response to repeated breath-hold apneas. Ten trained apnea divers and 10 intact and 7 splenectomized untrained persons repeated five maximal apneas (A1-A5) with face immersion in cold water, with 2 min interposed between successive attempts. Ultrasonic monitoring of the spleen and noninvasive cardiopulmonary measurements were performed before, between apneas, and at times 0, 10, 20, 40, and 60 min after the last apnea. Blood flows in splenic artery and splenic vein were not significantly affected by breath-hold apnea. The duration of apneas peaked after A3 (143, 127, and 74 s in apnea divers, intact, and splenectomized persons, respectively). A rapid decrease in spleen volume (∼20% in both apnea divers and intact persons) was mainly completed throughout the first apnea. The spleen did not recover in size between apneas and only partly recovered 60 min after A5. The well-known physiological responses to apnea diving, i.e., bradycardia and increased blood pressure, were observed in A1 and remained unchanged throughout the following apneas. These results show rapid, probably active contraction of the spleen in response to breath-hold apnea in humans. Rapid spleen contraction and its slow recovery may contribute to prolongation of successive, briefly repeated apnea attempts.

Relationship between vascular reactivity in vitro and blood flows in rats with cirrhosis

1999 ◽  
Vol 97 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Dominique PATERON ◽  
Frédéric OBERTI ◽  
Pascale LEFILLIATRE ◽  
Nary VEAL ◽  
Khalid A. TAZI ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Reactivity ◽  
Regional Blood Flow ◽  
Arterial Blood Flow ◽  
Blood Flows ◽  
Arterial Blood ◽  
Vascular Responsiveness ◽  
Microsphere Method ◽  
Radioactive Microsphere Method

In cirrhosis there is a hyperdynamic circulation, which occurs mainly in the systemic and splanchnic regions. Using isolated-vessel models, previous studies have shown reduced aortic reactivity to vasoconstrictors in rats with cirrhosis. The aim of the present study was to evaluate and compare the vascular responsiveness to phenylephrine in arterial rings and the blood flows from different regions in rats with cirrhosis and controls. Reactivity was studied in isolated thoracic aortic, superior mesenteric arterial and carotid arterial rings from sham-operated and bile-duct-ligated rats by measuring the cumulative concentration-dependent tension induced by phenylephrine (10-9–10-4 M). Blood flows were measured by the radioactive microsphere method. In rats with cirrhosis, a significant hyporeactivity to phenylephrine was observed in both the aorta and the superior mesenteric artery compared with the corresponding arteries of normal rats. This hyporesponsiveness was corrected by Nω-nitro-l-arginine (0.1 mM). In contrast, carotid artery reactivity and the responses to Nω-nitro-l-arginine were similar in the cirrhotic and control groups. In each case, cardiac output and mesenteric arterial blood flow were significantly higher in cirrhotic than in normal rats. Cerebral blood flows were not significantly different between the two groups. In cirrhotic rats, arterial hyporeactivity may be a consequence of increased regional blood flow and increased production of nitric oxide.

scholarly journals Continuous Measurement of Changes in Internal Carotid and Vertebral Arterial Blood Flow with Chronically Implanted Ultrasonic Doppler Probes in Anesthetized and Conscious Rabbits

1996 ◽  
Vol 16 (5) ◽  
pp. 1058-1067 ◽  
Author(s):  
Ying-Hui Yu ◽  
B-S Zhu ◽  
W. W. Blessing
Keyword(s):  
Blood Flow ◽  
Internal Carotid ◽  
Arterial Blood Flow ◽  
Noninvasive Measurements ◽  
Sagittal Sinus ◽  
Doppler Probe ◽  
Arterial Blood ◽  
Arterial Inflow ◽  
Conscious Rabbits ◽  
The Relationship

Chronically implanted ultrasonic Doppler flowmeters were used to obtain simultaneously recorded flow velocity signals from internal carotid and vertebral arteries, and the sagittal sinus, in rabbits. All three signals increased to 144 ± 7–215 ± 35% of baseline during hypercapnia (arterial Pco2 55 mmHg) in both anesthetized and conscious animals. During the period of change in inspired CO2, the relationship between simultaneously recorded mean internal carotid and mean sagittal sinus signals was linear, with the correlation ranging from 0.83 to 0.96. Since forebrain arterial inflow must approximate forebrain venous outflow, the high correlation between internal carotid and sagittal sinus signals indicates that these measures provide reliable and valid indices of cerebral blood flow (CBF). Vertebral and internal carotid angiography confirmed the location of Doppler probe. Chronically implanted ultrasonic Doppler flowmeters can, thus, provide continuous noninvasive measurements of cerebral arterial flow in both anesthetized and conscious rabbits.

scholarly journals Effect of Electrical Stimulation on Blood Flow in Calf Muscles in Different Body Positions

2018 ◽  
Vol 1 (96) ◽  
Author(s):  
Julius Dovydaitis ◽  
Albinas Grūnovas
Keyword(s):  
Blood Flow ◽  
Body Position ◽  
Venous Blood ◽  
The Body ◽  
Arterial Blood Flow ◽  
Reserve Capacity ◽  
Horizontal Position ◽  
Blood Flows ◽  
Arterial Blood ◽  
Electrical Muscle

Background.  In  most  studies  on  cardiovascular  system,  testing  of  subjects  was  performed  in  a  horizontal position. With the change of the body position, certain functional changes occur in the cardiovascular system. The aim of this study was to analyze the effect of electrical muscle stimulation (EMS) on arterial and venous blood flows.Methods. Eighteen athletes aged 19–23 performed two sessions of tests in horizontal and sitting positions. Changes in arterial and venous blood flows were recorded before and after EMS. In each session two occlusions were performed. In the horizontal position, the initial occlusion pressure of 20 mmHg was applied and as the balance in arterial and venous blood flow rates was reached, the additional pressure of 20 mmHg (40  mmHg in total). In the sitting position, the occlusion pressure of 40 and 20 mmHg was applied respectively (60 mmHg in total). In both sessions EMS was performed using the electrical stimulator Mioritm 021.Results. In both horizontal and vertical positions, the effect of EMS on arterial blood flow, venous reserve capacity and venous elasticity was insignificant. Arterial and venous blood flows was affected significantly by the change of the body position. In the sitting position, arterial blood flow was significantly (p < .05) lower compared to the horizontal position. Similar results were recorded in venous reserve capacity.Conclusion.  The  study  suggests  that  blood  flow  in  the  calf  muscles  is  affected  by  the  body  position  and hydrostatic pressure; arterial blood flow increases in the horizontal body position.Keywords:  electrical muscle stimulation (EMS), arterial blood flow, venous reserve capacity, venous elasticity

scholarly journals Clinical Study on the Effects of Different Infusion Solutions on Colloid Osmotic Pressure During Major Abdominal Surgery and Perioperative Albumin in Elderly Patients

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Chunyan Zhao ◽  
Cibo Chen ◽  
Bingchun Xia
Keyword(s):  
Abdominal Surgery ◽  
Elderly Patients ◽  
Osmotic Pressure ◽  
Colloid Osmotic Pressure ◽  
The Other ◽  
Major Abdominal Surgery ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
Group D

Objective: To explore the effects of different infusion schemes on colloid osmotic pressure during major abdominal surgery and perioperative albumin in elderly patients. Methods: 140 elderly patients of 65-80 years old undergoing major abdominal surgery were divided into 4 groups according to the method of random number table , and different proportions of crystals and colloids were given to different groups (group A: whole crystal, group B: crystal-colloid ratio 1 : 1, group C: crystal-colloid ratio 2: 1, Group D: crystal-colloid ratio 1: 2).  The plasma colloid osmotic pressure and level of albumin during perioperative period were monitored. Simultaneously observe the arterial blood pH, blood glucose, extubating time of endotracheal tube, postoperative feeding time, et al. Results: The total amount of liquid inputted in the group of whole crystal was 3056ml (3056 ± 253), which was significantly increased compared with other groups (P<0.01). At the same time, the colloid osmotic pressure decreased by 11.9 mmHg (11.9 ± 2.8), which was more obviously decreased than that of the other groups( B group3.9 ± 1.3, C group 1.5 ± 0.3, D group 4.7±2.1). The difference was a statistically significant(P<0.01). On the other day after surgery, the level of albumin decreased by an average of 4.3 g / L (4.5 ± 1.9) compared with that in group B before surgery, and group C decreased by 2.9 g / L (2.9 ± 1.2) in average, which was significantly different (P<0.05) from group A 10.2 g / L (10.2 ± 1.8). There was no statistically significant difference between group A and group D (P>0.05). And the other indexes were not significantly different between the two groups. Conclusion: This study found that different infusion solutions with different crystal-colloid ratios had an effect on perioperative colloid osmotic pressure and level of albumin.

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