Spatial heterogeneity of blood flow in the dog heart. II. Temporal stability in response to adrenergic stimulation

1996 ◽  
Vol 432 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Andreas Deussen ◽  
Thomas Lauer ◽  
Michael Sonntag ◽  
Jürgen Schrader ◽  
Christian W. Flesche
Keyword(s):  
Blood Flow ◽  
Spatial Heterogeneity ◽  
Temporal Stability ◽  
Adrenergic Stimulation ◽  
Dog Heart

Spatial heterogeneity of blood flow in the dog heart. I. Glucose uptake, free adenosine and oxidative/glycolytic enzyme activity

1996 ◽  
Vol 432 (3) ◽  
pp. 439-450 ◽  
Author(s):  
Michael Sonntag ◽  
Andreas Deussen ◽  
Jan Schultz ◽  
Robert Loncar ◽  
Jürgen Schrader ◽  
...  
Keyword(s):  
Blood Flow ◽  
Enzyme Activity ◽  
Spatial Heterogeneity ◽  
Glucose Uptake ◽  
Glycolytic Enzyme ◽  
Dog Heart

scholarly journals Spatial heterogeneity of the relation between resting-state connectivity and blood flow: An important consideration for pharmacological studies

2012 ◽  
Vol 35 (3) ◽  
pp. 929-942 ◽  
Author(s):  
Najmeh Khalili-Mahani ◽  
Matthias J. van Osch ◽  
Mark de Rooij ◽  
Christian F. Beckmann ◽  
Mark A. van Buchem ◽  
...  
Keyword(s):  
Blood Flow ◽  
Spatial Heterogeneity ◽  
Resting State ◽  
Pharmacological Studies ◽  
Resting State Connectivity

Right and left ventricular O2 uptake during hemodilution and beta-adrenergic stimulation

1993 ◽  
Vol 265 (5) ◽  
pp. H1769-H1777 ◽  
Author(s):  
G. J. Crystal ◽  
S. J. Kim ◽  
M. R. Salem
Keyword(s):  
Blood Flow ◽  
Blood Cells ◽  
Left Ventricular ◽  
Adrenergic Stimulation ◽  
O2 Uptake ◽  
Isovolemic Hemodilution ◽  
Content Difference ◽  
O2 Extraction ◽  
In Series ◽  
O2 Delivery

Myocardial O2 uptake (MVO2) and related variables were compared in right and left ventricles (RV and LV, respectively) during isovolemic hemodilution (HD) alone and combined with isoproterenol (Iso) infusion in 13 isoflurane-anesthetized open-chest dogs. Measurements of myocardial blood flow (MBF) obtained with radioactive microspheres were used to calculate MVO2. Lactate extraction (Lacext) was determined. The study consisted of two experimental series: 1) graded HD (dextran) to hematocrit (Hct) of 10% and 2) Iso (0.1 microgram.kg-1.min-1 iv) during moderate HD (Hct = 18 +/- 1%). In series 1, arteriovenous O2 content difference in both ventricles decreased in parallel with reduced arterial O2 content caused by HD, i.e., percent O2 extraction was constant; MVO2 was maintained by proportional increases in MBF. In series 2, Iso during moderate HD raised MVO2 (RV, +156%; LV, +80%). Higher MVO2 was satisfied by combination of increased MBF and O2 extraction in RV and by increased MBF alone in LV. Lacext remained consistent with adequate myocardial O2 delivery throughout study. Conclusions were that 1) both RV and LV tolerated extreme HD (Hct = 10%) because blood flow reserves were sufficient to fully compensate for reduced arterial O2 content; 2) significant cardiac reserve was evident during HD, which could be recruited Iso; and 3) because increase in MVO2 in RV caused by Iso in presence of HD was partially satisfied by increased O2 extraction, the absence of augmented O2 extraction during HD alone was not due to impaired release of O2 from diluted red blood cells.(ABSTRACT TRUNCATED AT 250 WORDS)

β-adrenergic stimulation and abdominal subcutaneous fat blood flow in lean, obese, and reduced-obese subjects

Metabolism ◽  
1995 ◽  
Vol 44 (2) ◽  
pp. 183-187 ◽  
Author(s):  
E.E. Blaak ◽  
M.A. van Baak ◽  
G.J. Kemerink ◽  
M.T.W. Pakbiers ◽  
G.A.K. Heidendal ◽  
...  
Keyword(s):  
Blood Flow ◽  
Subcutaneous Fat ◽  
Adrenergic Stimulation ◽  
Obese Subjects

Modulation of endothelium-dependent responses by chronic alterations of blood flow

1986 ◽  
Vol 251 (3) ◽  
pp. H520-H527 ◽  
Author(s):  
V. M. Miller ◽  
L. L. Aarhus ◽  
P. M. Vanhoutte
Keyword(s):  
Blood Flow ◽  
Femoral Artery ◽  
Inverse Relationship ◽  
Contractile Response ◽  
Adenosine Diphosphate ◽  
Elevated Blood ◽  
Adrenergic Stimulation ◽  
Arteries And Veins ◽  
Endothelium Dependent Relaxation

To determine whether the blood flow and O2 tension to which a blood vessel is chronically exposed could modulate endothelium-dependent responses, these parameters were altered in the dog either by causing partial occlusion of the femoral artery or by creating a fistula between the femoral artery and vein. Blood flow was reduced by 75% in the clamped artery; mean arterial pressure was unchanged. In the vessels proximal to the fistula, blood flow was elevated and O2 tensions were similar in the vein and artery. After 6 wk the femoral arteries and veins were excised, and their endothelium-dependent responses were studied in vitro. The endothelium-dependent relaxations to acetylcholine, adenosine diphosphate, and alpha 2-adrenergic stimulation were augmented in fistula-operated compared with sham-operated arteries. The responses to these agents in the clamp-operated vessels were not different from those of the sham-operated ones. Relaxation to arachidonic acid in the arteries showed an inverse relationship to blood flow. In the veins proximal to the fistula, the endothelium-dependent relaxations to acetylcholine were augmented and an endothelium-dependent relaxation to alpha 2-adrenergic stimulation was present; only a contractile response was observed in veins from the sham-operated limb in response to the latter. These studies suggest a pattern of increased endothelium-dependent relaxation in vessels exposed to chronically elevated blood flow.

Increase of ovarian progesterone secretion by β2-adrenergic stimulation in oestrous rats

1982 ◽  
Vol 101 (2) ◽  
pp. 268-272 ◽  
Author(s):  
Béla Zsolnai ◽  
Bertalan Varga ◽  
Edit Horváth
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Adrenergic Receptors ◽  
Hormone Secretion ◽  
Regulatory Role ◽  
Blood Levels ◽  
Ovarian Hormone ◽  
Adrenergic Stimulation ◽  
Venous Outflow ◽  
Progesterone Secretion

Abstract. Oestrous rats were anaesthetized with pentobarbital and one of the femoral arteries, femoral veins and utero-ovarian veins were cannulated. Five min blood fractions were collected from the ovary for 50 min. Following two control fractions fenoterol, noradrenaline, isoproterenol (0.5 μg/min) or 0.9% NaCl (0.02 ml/min) were infused iv for 40 min. In a group of oestrous animals fenoterol was given locally to the ovarian bursa. Blood pressure and the ovarian venous outflow were continuously recorded and blood levels of progesterone (P) and oestradiol-17β (E2) were determined by RIA. Fenoterol administered iv increased P secretion without altering ovarian blood flow, whereas noradrenaline and isoproterenol had no effect on P secretion. Fenoterol administered locally stimulated both P and E2 secretion, and this was prevented by iv infusion of propranolol. It is suggested that ovarian β2-adrenergic receptors have a regulatory role in ovarian hormone secretion.

Angiotensin II and alpha-agonist. I. Responses of ovine fetoplacental vasculature

1990 ◽  
Vol 259 (2) ◽  
pp. H464-H472 ◽  
Author(s):  
T. Yoshimura ◽  
R. R. Magness ◽  
C. R. Rosenfeld
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Vascular Resistance ◽  
Plasma Catecholamines ◽  
Ang Ii ◽  
Adrenergic Stimulation ◽  
Umbilical Blood ◽  
Steady State Responses ◽  
Maternal Responses ◽  
Dose Dependent

During ovine pregnancy the uteroplacental vasculature is less responsive to angiotensin II (ANG II)-induced vasoconstriction than the systemic vasculature, whereas responses to alpha-agonists are just the opposite. Comparisons of fetal systemic and placental vascular responses to these agents are not well described, nor have they been compared with maternal responses. We determined steady-state responses to fetal infusions (5-7 min) of ANG II (0.023-5.73 micrograms/min) and phenylephrine (PHEN, 0.031-7.64 micrograms/min), continuously monitoring mean arterial pressure (MAP), heart rate (HR), and umbilical blood flow (UmBF). Although both vasoconstrictors caused dose-dependent increases in MAP and umbilical vascular resistance (UmVR), responsiveness (delta MAP and delta UmVR) to ANG II (mol/min) was 35- to 60-fold greater than to PHEN. ANG II caused dose-dependent decreases in UmBF (2-48%); PHEN had minimal effects except at the highest dose, UmBF decreasing only 18%. Although patterns of fetal responses of MAP, UmBF, and UmVR to ANG II resembled maternal responses of MAP and uterine blood flow and uterine vascular resistance, the former were greatly attenuated. Similar observations were made with PHEN for UmBF and UmVR but not MAP. ANG II is a more potent fetal systemic and placental vasoconstrictor than PHEN; however, compared with those of the mother the responses are attenuated. Moreover, the fetoplacental vascular bed appears unresponsive to alpha-adrenergic stimulation, possibly reflecting a mechanism for maintaining UmBF when plasma catecholamines are elevated.

Reduced effect of phenylephrine on regional myocardial function and O2 consumption in experimental LVH

1995 ◽  
Vol 268 (3) ◽  
pp. H1202-H1207
Author(s):  
A. Roitstein ◽  
B. V. Cheinberg ◽  
J. Kedem ◽  
J. Tse ◽  
H. R. Weiss ◽  
...  
Keyword(s):  
Blood Flow ◽  
Radioligand Binding ◽  
Dissociation Constants ◽  
Regional Blood Flow ◽  
Left Ventricular ◽  
Adrenergic Blockade ◽  
O2 Consumption ◽  
Adrenergic Stimulation ◽  
Alpha Adrenoceptor ◽  
Myocardial O2 Consumption

In a dog model of left ventricular hypertrophy (LVH) created by aortic valve plication, we examined the hypothesis that regional myocardial inotropic and metabolic responses to alpha-adrenergic stimulation would be diminished due to decreased alpha-adrenoceptor number. After systemic beta-adrenergic blockade, phenylephrine (PE, 5 micrograms.kg-1.min-1) was infused into the left anterior descending artery in eight LVH and nine control open-chest anesthetized dogs. The circumflex region served as control. In both regions, local segment work was calculated as the integrated products of force (miniature transducer) and segment shortening (ultrasonic crystals). Local myocardial O2 consumption was calculated from regional blood flow (microspheres) and O2 saturation (microspectrophotometry). A saturation radioligand binding assay was used to determine adrenoceptor number and affinity. In control animals in the treated region, PE increased work from 815 +/- 140 to 1,493 +/- 149 g.mm.min-1. In LVH, work was not significantly altered (688 +/- 142 vs. 730 +/- 149 g.mm.min-1). Regional blood flow was elevated in controls (81 +/- 10 to 141 +/- 24 ml.min-1.100 g-1) but was not changed in LVH (105 +/- 12 vs. 123 +/- 18 ml.min-1.100 g-1). In controls, but not in LVH, myocardial O2 consumption was almost doubled during PE infusion (6.2 +/- 0.9 vs. 12.0 +/- 2.1 ml O2.min-1.100 g-1). alpha-Adrenoceptor number and dissociation constants values were not different between control and LVH (15.7 +/- 2.8 vs. 16.4 +/- 2.7 fmol/mg protein; 13.2 +/- 3.4 vs. 16.9 +/- 4.3 nm, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

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