Hemodynamic effects of a combination of clonidine and propranolol in conscious cirrhotic rats

1989 ◽  
Vol 67 (10) ◽  
pp. 1369-1372 ◽  
Author(s):  
Dominique Roulot ◽  
Christophe Gaudin ◽  
Alain Braillon ◽  
Tatsuya Sekiyama ◽  
Yannick Bacq ◽  
...  
Keyword(s):  
Blood Flow ◽  
Portal Hypertension ◽  
Portal Pressure ◽  
Biliary Cirrhosis ◽  
Hemodynamic Effects ◽  
Hemodynamic Changes ◽  
Flow Measurements ◽  
Before And After ◽  
Radioactive Microsphere Method ◽  
Blood Flow Measurements

The hemodynamic effects of the combination of clonidine and propranolol were studied in conscious rats with portal hypertension owing to secondary biliary cirrhosis. Pressure and blood flow measurements (radioactive microsphere method) were performed in three groups of eight rats before and after drug administration. The combined effects of clonidine (2 μg/100 g body wt., i.v.) and propranolol (0.2 mg/min for 10 min) were compared with those observed after administration of either clonidine alone or propranolol alone. The association of clonidine and propranolol induced significant decreases in portal pressure (30%) and portal tributary blood flow (43%), the magnitude of these changes being significantly more marked than that after administration of either clonidine alone (12 and 20%, respectively) or propranolol alone (16 and 17%, respectively). After the combination, no significant change in arterial pressure was observed, but cardiac output significantly decreased and systemic vascular resistance significantly increased. Renal blood flow decreased to a similar extent (40%) in the three groups. These findings indicate that the combination of clonidine and propranolol is more effective for reversing splanchnic hemodynamic changes than clonidine alone or propranolol alone. The additive effects of this association are in agreement with the action of clonidine and propranolol at different levels (central and peripheral) and on different receptors (α and β). It suggests that an increase in sympathetic activity may play a major role in hemodynamic changes observed in experimental cirrhosis.Key words: portal hypertension, cirrhosis, splanchnic blood flow, α2-adrenergic agonist, β-blocker.

scholarly journals Improved brain perfusion after electrical cardioversion of atrial fibrillation

EP Europace ◽  
2019 ◽  
Vol 22 (4) ◽  
pp. 530-537 ◽  
Author(s):  
Marianna Gardarsdottir ◽  
Sigurdur Sigurdsson ◽  
Thor Aspelund ◽  
Valdis Anna Gardarsdottir ◽  
Lars Forsberg ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Atrial Fibrillation ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Brain Perfusion ◽  
Resonance Imaging ◽  
Flow Measurements ◽  
Before And After ◽  
Blood Flow Measurements

Abstract Aims Atrial fibrillation (AF) has been associated with reduced brain volume, cognitive impairment, and reduced cerebral blood flow. The causes of reduced cerebral blood flow in AF are unknown, but no reduction was seen in individuals without the arrhythmia in a previous study. The aim of this study was to test the hypothesis that brain perfusion, measured with magnetic resonance imaging (MRI), improves after cardioversion of AF to sinus rhythm (SR). Methods and results All patients undergoing elective cardioversion at our institution were invited to participate. A total of 44 individuals were included. Magnetic resonance imaging studies were done before and after cardioversion with both brain perfusion and cerebral blood flow measurements. However, 17 did not complete the second MRI as they had a recurrence of AF during the observation period (recurrent AF group), leaving 17 in the SR group and 10 in the AF group to complete both measurements. Brain perfusion increased after cardioversion to SR by 4.9 mL/100 g/min in the whole brain (P < 0.001) and by 5.6 mL/100 g/min in grey matter (P < 0.001). Cerebral blood flow increased by 58.6 mL/min (P < 0.05). Both brain perfusion and cerebral blood flow remained unchanged when cardioversion was unsuccessful. Conclusion In this study of individuals undergoing elective cardioversion for AF, restoration, and maintenance of SR for at least 10 weeks after was associated with an improvement of brain perfusion and cerebral blood flow measured by both arterial spin labelling and phase contrast MRI. In those individuals where cardioversion was unsuccessful, there was no change in perfusion or blood flow.

REPRODUCIBILITY OF INTESTINAL BLOOD FLOW MEASUREMENTS BEFORE AND AFTER 1 HOUR CYCLING

1995 ◽  
Vol 27 (Supplement) ◽  
pp. S65
Author(s):  
Peters HPF ◽  
D de Leeuw ◽  
R C Lapham ◽  
E Bol ◽  
M S van Leeuwen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Intestinal Blood Flow ◽  
Flow Measurements ◽  
Before And After ◽  
Blood Flow Measurements

Accuracy of portal and forearm blood flow measurements in the assessment of the portal pressure response to propranolol

1997 ◽  
Vol 27 (3) ◽  
pp. 496-504 ◽  
Author(s):  
Agustín Albillos ◽  
María Perez-Paramo ◽  
Guillermo Cacho ◽  
Jerónimo Iborra ◽  
Jose Luis Calleja ◽  
...  
Keyword(s):  
Blood Flow ◽  
Forearm Blood Flow ◽  
Portal Pressure ◽  
Pressure Response ◽  
Flow Measurements ◽  
Blood Flow Measurements

Evolution of portal hypertension and mechanisms involved in its maintenance in a rat model

1985 ◽  
Vol 248 (6) ◽  
pp. G618-G625 ◽  
Author(s):  
E. Sikuler ◽  
D. Kravetz ◽  
R. J. Groszmann
Keyword(s):  
Blood Flow ◽  
Portal Hypertension ◽  
Portal Vein ◽  
Rat Model ◽  
Portal Pressure ◽  
Portal System ◽  
Hypertensive Rats ◽  
Hemodynamic Changes ◽  
Sequence Of Events ◽  
Radioactive Microsphere

In rats with portal hypertension induced by partial ligation of the portal vein, we have recently demonstrated an increased portal venous inflow that becomes an important factor in the maintenance of portal hypertension. The sequence of events that leads into this circulatory disarray is unknown. We evaluated chronologically the chain of hemodynamic changes that occurred after portal hypertension was induced by partial ligation of the portal vein. In this model it is possible to follow, from the initiation of the portal-hypertensive state, the interaction between blood flow and resistance in the portal system as well as the relation between the development of portal-systemic shunting and the elevated portal venous inflow. The study was performed in 45 portal-hypertensive rats and in 29 sham-operated rats. Blood flow and portal-systemic shunting were measured by radioactive microsphere techniques. The constriction of the portal vein was immediately followed by a resistance-induced portal hypertension characterized by increased portal resistance (9.78 +/- 0.89 vs. 4.18 +/- 0.71 dyn X s X cm-5 X 10(4), mean +/- SE, P less than 0.01), increased portal pressure (17.7 +/- 0.9 vs. 9.5 +/- 0.6 mmHg, P less than 0.001), and decreased portal venous inflow (3.93 +/- 0.26 vs. 6.82 +/- 0.49 ml X min-1 X 100 g body wt-1, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effects of Venesection on Cerebral Function in Chronic Lung Disease

1980 ◽  
Vol 7 (4) ◽  
pp. 293-296 ◽  
Author(s):  
R. Bornstein ◽  
D. Menon ◽  
E. York ◽  
B. Sproule ◽  
C. Zak
Keyword(s):  
Blood Flow ◽  
Neuropsychological Testing ◽  
Chronic Obstructive ◽  
Mental Function ◽  
Cerebral Function ◽  
Regional Cerebral Blood ◽  
Flow Measurements ◽  
Obstructive Pulmonary Disease ◽  
Before And After ◽  
Blood Flow Measurements

SUMMARY:Regional cerebral blood flow measurements and neuropsychological testing were conducted before and after venesection on 6 patients with polycythemia secondary to chronic obstructive pulmonary disease. Venesection resulted in lowered viscosity and hematocrit, and an accompanying improvement in cerebral perfusion and mental function. Blood flow was significantly increased in the left cerebral hemisphere following phlebotomy, and there was significant improvement in sensory I mental function. Cerebral function would appear to be related to blood flow alterations influenced by the viscosity of the blood.

Renal artery stenosis: grading of hemodynamic changes with cine phase-contrast MR blood flow measurements.

Radiology ◽  
1997 ◽  
Vol 203 (1) ◽  
pp. 45-53 ◽  
Author(s):  
S O Schoenberg ◽  
M V Knopp ◽  
M Bock ◽  
F Kallinowski ◽  
A Just ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Artery ◽  
Renal Artery Stenosis ◽  
Phase Contrast ◽  
Artery Stenosis ◽  
Hemodynamic Changes ◽  
Flow Measurements ◽  
Blood Flow Measurements ◽  
Cine Phase Contrast

Effect of exercise on cardiac output and distribution of uterine blood flow in pregnant ewes

1976 ◽  
Vol 40 (5) ◽  
pp. 725-728 ◽  
Author(s):  
L. B. Curet ◽  
J. A. Orr ◽  
H. G. Rankin ◽  
T. Ungerer
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Stroke Volume ◽  
Physical Training ◽  
Exercise Stress ◽  
Compensatory Mechanism ◽  
Uterine Blood Flow ◽  
Flow Measurements ◽  
Before And After ◽  
Blood Flow Measurements

This study was designed to determine what effect physical training has on heart rate and stroke volume responses to exercise stress and to determine if exercise altered the distribution of uterine blood flow. Measurements were made in ten pregnant ewes at rest and immediately following exercise on a treadmill. Five ewes underwent physical training for 3 wk prior to measurement. An increase in heart rate with no change in stroke volume was observed following exercise in both trained and untrained ewes. Total uterine blood flow was not changed following exercise, but distribution was altered in favor of the placenta. Blood flow was evenly distributed within the placenta before and after exercise. The redistribution of flow to the placenta that occurs after exercise. tphe redistribution of flow to the placenta that occurs after exercise might represent a compensatory mechanism for the fetus.

scholarly journals Multiple blood flow measurements before and after carotid artery stenting via phase-contrast magnetic resonance imaging: An observational study

PLoS ONE ◽  
2018 ◽  
Vol 13 (4) ◽  
pp. e0195099 ◽  
Author(s):  
Hisashi Tanaka ◽  
Yoshiyuki Watanabe ◽  
Hajime Nakamura ◽  
Hiroto Takahashi ◽  
Atsuko Arisawa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Phase Contrast ◽  
Resonance Imaging ◽  
Flow Measurements ◽  
Before And After ◽  
Contrast Magnetic Resonance ◽  
Multiple Blood ◽  
Blood Flow Measurements

scholarly journals Passive hallux adduction decreases lateral plantar artery blood flow: a preliminary study of the potential influence of narrow toe box shoes

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Julia L. Jacobs ◽  
Sarah T. Ridge ◽  
Dustin A. Bruening ◽  
K. Annie Brewerton ◽  
Jayson R. Gifford ◽  
...  
Keyword(s):  
Blood Flow ◽  
Artery Blood Flow ◽  
Arch Height ◽  
Abductor Hallucis ◽  
Flow Measurements ◽  
Medial Side ◽  
Negative Change ◽  
Plantar Artery ◽  
Before And After ◽  
Blood Flow Measurements

Abstract Background Blood flow is essential in maintaining tissue health. Thus, compromised blood flow can prevent tissue healing. An adducted hallux, as seen inside a narrow shoe, may put passive tension on the abductor hallucis, compressing the lateral plantar artery into the calcaneus and restricting blood flow. The purposes of this study were to compare lateral plantar artery blood flow before and after passive hallux adduction and to compare blood flow with arch height. Methods Forty-five healthy volunteers (20 female, 25 male; age = 24.8 ± 6.8 yr; height = 1.7 ± 0.1 m; weight = 73.4 ± 13.5 kg) participated in this cross-over design study. Arch height index (AHI) was calculated, and blood flow measurements were obtained using ultrasound (L8-18i transducer, GE Logiq S8). The lateral plantar artery was imaged deep to abductor hallucis for 120 s: 60 s at rest, then 60 s of passive hallux adduction. Maximal passive hallux adduction was performed by applying pressure to the medial side of the hallux. Blood flow was calculated in mL/min, and pre-passive hallux adduction was compared to blood flow during passive hallux adduction. Results Log transformed data was used to run a paired t-test between the preadduction and postadduction blood flow. The volume of blood flow was 22.2% lower after passive hallux adduction compared to before (− 0.250 ± 0.063, p < 0.001). As AHI decreased, there was a greater negative change in blood flow. As baseline blood flow increased, there was also a greater negative change in blood flow. Conclusions Our preliminary findings of decreased blood flow through passive hallux adduction indicate conditions that elicit passive hallux adduction (e.g. wearing narrow-toed shoes) may have important effects on foot blood flow. Individuals with lower AHI appear to have a greater risk of decreased blood flow with passive hallux adduction.

Validation of fluorescent-labeled microspheres for measurement of relative blood flow in severely injured lungs

1999 ◽  
Vol 87 (6) ◽  
pp. 2381-2385 ◽  
Author(s):  
Matthias Hübler ◽  
Jennifer E. Souders ◽  
Erin D. Shade ◽  
Michael P. Hlastala ◽  
Nayak L. Polissar ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oleic Acid ◽  
Lung Injury ◽  
Scintillation Counter ◽  
Severely Injured ◽  
Flow Measurements ◽  
Fluorescent Microsphere ◽  
Before And After ◽  
Microsphere Method ◽  
Blood Flow Measurements

The aim of the study was to validate a nonradioactive method for relative blood flow measurements in severely injured lungs that avoids labor-intensive tissue processing. The use of fluorescent-labeled microspheres was compared with the standard radiolabeled-microsphere method. In seven sheep, lung injury was established by using oleic acid. Five pairs of radio- and fluorescent-labeled microspheres were injected before and after established lung injury. Across all animals, 175 pieces were selected randomly. The radioactivity of each piece was determined by using a scintillation counter. The fluorescent dye was extracted from each piece with a solvent without digestion or filtering. The fluorescence was determined with an automated fluorescent spectrophotometer. Perfusion was calculated for each piece from both the radioactivity and fluorescence and volume normalized. Correlations between flow determined by the two methods were in the range from 0.987 ± 0.007 (SD) to 0.991 ± 0.002 (SD) after 9 days of soaking. Thus the fluorescent microsphere technique is a valuable tool for investigating regional perfusion in severely injured lungs and can replace radioactivity.

Sign in / Sign up

Export Citation Format

Share Document