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.

Abstract P214: Mechanotransduction And Uterine Blood Flow In Preeclampsia- The Role Of Piezo 1 Ion Channels.

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Olufunke O Arishe ◽  
Vanessa Dela Justina ◽  
Fernanda B Priviero ◽  
Clinton R Webb
Keyword(s):  
Blood Flow ◽  
Vascular Remodeling ◽  
Vascular Reactivity ◽  
Small Diameter ◽  
Subsequent Development ◽  
Normal Pregnancy ◽  
Arterial Blood Flow ◽  
Pregnant Rats ◽  
Arterial Blood

Background: There is a large increase in uterine arterial blood flow during normal pregnancy. Structural and cellular adjustments occur in the uterine vasculature during pregnancy to accommodate this increased blood flow through a process is known as ‘vascular remodeling’. The etiology of preeclampsia involves aberrant placentation and vascular remodeling leading to reduced uteroplacental perfusion. However, the underlying source of the deficient vascular remodeling and the subsequent development of preeclampsia remains to be fully understood. Piezo 1 channels have been shown to be highly expressed in vascular smooth muscle cells of small-diameter arteries and play a role in the structural remodeling of the arteries. Studies have also shown that Piezo 1 is present in uterine arteries and it’s not exclusive to the endothelial cells. Hypothesis: This study tests the hypothesis that reduced Piezo 1 activity contributes to decreased uterine vascular relaxation in hypertensive pregnant rats. Methods: Hypertension was induced by treating the pregnant rats with synthetic CpG ODN (ODN 2395) via three intraperitoneal injections (100μg/rats) while the normotensive controls were treated with saline (vehicle) on the 14 th , 17th and 18 th days of pregnancy. Mean arterial pressure (MAP) was measured. In vitro vascular reactivity of uterine arterial (UA) ring segments were evaluated using isometric wire myograph system. Rings were pre-contracted with 3μM phenylephrine (PE), concentration responses of to Yoda1; a pharmacological agonist of Piezo 1 channel were compared. Statistical analysis was performed using nonlinear regression and Students’ t-test. Results: Our results show that MAP was greater in rats treated with ODN2395 vs untreated rats (112 ± 1 vs 90 ± 1 p =0.0004). Concentration-dependent relaxation responses to Yoda1 were greater in UAs of untreated rats compared to those treated with ODN2395 (EC50 0.06571 ± 0.09781 vs. 0.5774 ± 0.1187 p =0.0018). Conclusion: These results suggest that the reduced vasodilation in pregnancy-associated hypertension may be due to a reduced Piezo 1 channel activity.

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 circulatory responses to hypocapnia and hypercapnia in bar-headed geese

1986 ◽  
Vol 250 (3) ◽  
pp. R499-R504 ◽  
Author(s):  
F. M. Faraci ◽  
M. R. Fedde
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Pectoral Muscle ◽  
Blood Flows ◽  
Arterial Blood ◽  
Blood Flow Reduction ◽  
Extreme Altitude ◽  
Anser Indicus ◽  
O2 Delivery

To investigate mechanisms that may allow birds to tolerate extreme high altitude (hypocapnic hypoxia), we examined the effects of severe hypocapnia and moderate hypercapnia on regional blood flow in bar-headed geese (Anser indicus), a species that flies at altitudes up to 9,000 m. Cerebral, coronary, and pectoral muscle blood flows were measured using radioactive microspheres, while arterial CO2 tension (PaCO2) was varied from 7 to 62 Torr in awake normoxic birds. Arterial blood pressure was not affected by hypocapnia but increased slightly during hypercapnia. Heart rate did not change during alterations in PaCO2. Severe hypocapnia did not significantly alter cerebral, coronary, or pectoral muscle blood flow. Hypercapnia markedly increased cerebral and coronary blood flow, but pectoral muscle blood flow was unaffected. The lack of a blood flow reduction during severe hypocapnia may represent an important adaptation in these birds, enabling them to increase O2 delivery to the heart and brain at extreme altitude despite the presence of a very low PaCO2.

Hemodynimic effects of systemic and central administration of clonidine in the monkey

1975 ◽  
Vol 228 (4) ◽  
pp. 1276-1279 ◽  
Author(s):  
P Bolme ◽  
RP Forsyth ◽  
T Ishizaki ◽  
KL Melmon
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Systemic Arterial Pressure ◽  
Intraventricular Injection ◽  
Central Administration ◽  
New Information ◽  
Before And After ◽  
Microsphere Method ◽  
Radioactive Microsphere Method

Systemic and regional hemodynamic changes were measured in restrained, conscious rhesus monkeys with indwelling arterial and venous catheters before and after clonidine (5 and 15 mug/kg) was slowly infused intravenously or smaller doses (2 mug/kg) were injected into a lateral cerebral ventricle. Dye-dilution cardiac outputs and the complete distribution of cardiac output were obtained intermittently with the use of the radioactive microsphere method. After the higher intravenous dose and the intraventricular injection, systemic arterial pressure was significantly lowered for 30-45 min. Both of these groups had similar changes in the redistribution of cardiac output and blood flow that outlasted the hypotensive period. Blood flow was maintained or increased in the hepatic and renal arteries at the expense of skin; flow to skeletal muscle and brain also decreased during the first hour. These data support previous studies that indicate that the primary action of clonidine is in the central nervous system and, in addition, add new information about the regional blood flow changes evoked by clonidine.

Age-related changes in regional blood flow in the rat

1985 ◽  
Vol 249 (3) ◽  
pp. H485-H491 ◽  
Author(s):  
R. F. Tuma ◽  
G. L. Irion ◽  
U. S. Vasthare ◽  
L. A. Heinel
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Index ◽  
Regional Blood Flow ◽  
Adult Rats ◽  
Blood Flows ◽  
Arterial Blood ◽  
Anesthetized Rats ◽  
Regional Blood Flows ◽  
Central Hemodynamic

The purpose of this investigation was to characterize the changes in regional blood flow and central hemodynamic measures that occur in the rat as a result of the aging process. The isotope-labeled microsphere technique was used to measure cardiac output and regional blood flows in conscious and anesthetized adult (12 mo) and senescent (24 mo) Fischer 344 virgin female rats. No significant changes were observed in central hemodynamic measurements or regional blood flows in conscious rats with the exception of a 25% reduction in splenic blood flow. Pentobarbital anesthesia significantly reduced cardiac index and heart rate but elevated total peripheral resistance and mean arterial blood pressure. There was a decrease in blood flow to skeletal muscle, spleen, duodenum, stomach, and brain tissue samples and increased hepatic arterial blood flow in both age groups. The use of anesthesia caused a greater reduction in the cardiac index and brain blood flow in the senescent anesthetized rats than in the adult rats. Heart and kidney blood flows were decreased by anesthesia in the senescent rats but not in the adult rats. Skeletal muscle blood flow, however, was significantly greater in the senescent anesthetized rats than in the younger anesthetized animals. Although body weight and organ weights of the liver, spleen, kidneys, stomach, heart, and brain were significantly greater for the senescent rats, no differences could be demonstrated in tibial length or lean body mass.

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

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.

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