Blood flow distribution in dogs during hypothermia and posthypothermia

1978 ◽  
Vol 234 (6) ◽  
pp. H706-H710 ◽  
Author(s):  
T. Anzai ◽  
M. D. Turner ◽  
W. H. Gibson ◽  
W. A. Neely
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Striated Muscle ◽  
Bronchial Artery ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Blood Flows ◽  
Endocrine Organs ◽  
Specific Reactions ◽  
Almost All

Blood flow distribution in tissues of mongrel dogs during hypothermia was studied with radionuclide-tagged microspheres. The animals were cooled at 21 degrees C and rewarmed under thiamylal sodiuni anesthesia. During hypothermia, cardiac output fell to 20% of the control; the highest rate of blood flow relative to normothermic values was observed in the subendocardium of the left ventricle, and the lowest in the hypophysis. Each tissue showed specific reactions to hypothermia. During hypothermia the myocardial and brain-stem blood flows were about 40% of the control; almost all of the digestive tract, striated muscle, adrenal gland, and hypophysis blood flows were maintained at 20% or less of the control. After rewarming, cardiac output recovered to values significantly lower than control. The myocardium, brain, renal cortex, and striated and smooth muscle recovered to control levels; however, blood flow to the digestive organs, bronchial artery flow to the lung, and flow to the endocrine organs did not completely recover by 2 after rewarming.

THE EFFECT OF EXERCISE ON THE CARDIAC OUTPUT AND BLOOD FLOW DISTRIBUTION OF THE LARGESCALE SUCKER CATOSTOMUS MACROCHEILUS

1993 ◽  
Vol 183 (1) ◽  
pp. 301-321 ◽  
Author(s):  
A. S. Kolok ◽  
M. R. Spooner ◽  
A. P. Farrell
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Swimming Performance ◽  
Flow Distribution ◽  
Fold Increase ◽  
Blood Flow Distribution ◽  
Dramatic Decline ◽  
Red Muscle ◽  
Catostomus Macrocheilus ◽  
A Current

Cardiac output (Q.) and blood flow distribution were measured in adult largescale suckers at rest and while swimming. Cardiac output was directly measured using an ultrasonic flowprobe in fish during the summer (16°C), fall (10°C) and winter (5°C). Largescale suckers were adept at holding station against a current without swimming and, when engaged in this behavior, they did not significantly increase Q. relative to that found in fish in still water. When fish began to swim, Q. increased significantly. From 16 to 10°C, the critical swimming speed (Ucrit), maximum Q. and scope for Q. of the suckers did not change. However, from 10 to 5°C all three traits were significantly reduced. Thus, these fish respond to variation in water temperature in two different ways. From 16 to 10°C, the fish compensate perfectly for the change in temperature with respect to cardiac and swimming performance. From 10 to 5°C, however, largescale suckers experience a dramatic decline in cardiac and swimming performance that may be associated with a quiescent overwintering strategy. Blood flow distribution in the fish at rest and while swimming was measured at 16°C using injection of colored microspheres. In the resting fish, over 10 % of the microspheres were recovered from the kidney and over 43 % were recovered from white muscle. When the fish were swimming, there was a 60-fold increase in blood flow to the red muscle while blood flow to all other tissues remained consistent with that at rest.

Blood flow distribution in tissues of perfused rat hindlimb preparations

1986 ◽  
Vol 250 (4) ◽  
pp. E441-E448 ◽  
Author(s):  
J. Gorski ◽  
D. A. Hood ◽  
R. L. Terjung
Keyword(s):  
Blood Flow ◽  
Large Fraction ◽  
Flow Distribution ◽  
Muscle Performance ◽  
Blood Flow Distribution ◽  
Tissue Mass ◽  
Contracting Muscle ◽  
Trunk Region ◽  
Blood Flows ◽  
Fast Twitch

Aerobic muscle metabolism during concentrations requires adequate blood flow and oxygen delivery. Since the perfused rat hindquarter (HQ) has become widely used for muscle stimulation, we examined the blood flow distribution, using 15 microns radiolabeled microspheres, and oxygen consumption of the HQ, using different commonly used perfusion protocols. Perfusion via the abdominal aorta resulted in well-matched (r = 0.90) blood flows between tissues of both hindlimbs that were proportional to total perfusion inflow. Blood flows to the high-oxidative fast-twitch and slow-twitch red muscle sections were three- to fourfold greater than flows to sections of low-oxidative fast-twitch white muscle. However, a large fraction (28%) of the total inflow went to the trunk region, even though all apparent arterial branches to the trunk region were ligated. This trunk mass accounts for at least 40% of the total metabolic responses of the HQ and diverts a large blood flow that is often presumed to supply the hindlimbs. As a result, muscle performance of the distal hindlimb muscle during stimulation can be inordinately poor. Ligation of the iliac artery to the contralateral limb improves blood flow to the remaining hindlimb but does not eliminate trunk blood flow. In contrast, perfusion via the femoral artery restricted 95% of the inflow to the single hindlimb, thereby reducing the tissue mass perfused. Blood flow to the distal limb musculature was high, resulting in an enhanced muscle performance. Thus single hindlimb perfusion provides a preparation where the contracting muscle is a large fraction of the total tissue, and the venous effluent better reflects the metabolic events in the contracting muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Cardiac Output and Genital Blood Flow Distribution During the Preovulatory Period in Rabbits1

1975 ◽  
Vol 13 (5) ◽  
pp. 581-586 ◽  
Author(s):  
Luis Blasco ◽  
Chung-Hsiu Wu ◽  
George L. Flickinger ◽  
David Pearlmutter ◽  
George Mikhail
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Flow Distribution ◽  
Blood Flow Distribution

Regional blood flow distribution during the Cushing response: alterations with adrenergic blockade

1985 ◽  
Vol 248 (1) ◽  
pp. H98-H108
Author(s):  
D. G. van Wylen ◽  
L. G. D'Alecy
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Flow Distribution ◽  
Peripheral Tissue ◽  
Systemic Hypertension ◽  
Tissue Blood Flow ◽  
Blood Flow Distribution ◽  
Beta Receptor ◽  
Cushing Response

Regional blood flow distribution (microspheres) and cardiac output (CO, thermal dilution) were measured during the Cushing response in unblocked (UB), beta-receptor-blocked (BB, 2 mg/kg propranolol iv), or alpha-receptor blocked (AB, 0.5 mg/kg + 0.5 mg X kg-1 X min-1 phentolamine iv) chloralose-anesthetized dogs. Intracranial pressure was increased to 150 mmHg by infusion of temperature-controlled artificial cerebrospinal fluid into the cisterna magna. Similar increases in mean arterial pressure were seen in UB and BB, but in AB a Cushing response could not be sustained. In UB, cerebral blood flow (CBF) decreased 50%, coronary blood flow (CoBF) increased 120%, and peripheral tissue blood flow was reduced only in the kidneys (18%) and the intestines (small 22%, large 35%). Blood flow to the other viscera, skin, and skeletal muscle was unchanged. CO (16%) and heart rate (HR, 38%) decreased, and total peripheral resistance (TPR, 68%) and stroke volume (SV, 38%) increased. In BB, CBF decreased 50%, CoBF decreased 20%, and blood flow was reduced 40-80% in all peripheral tissues. CO (69%) and HR (62%) decreased, TPR increased 366%, and SV was unchanged. We conclude that the Cushing response in UB animals combines an alpha-receptor-mediated vasoconstriction with a beta-receptor cardiac stimulation. The beta-mechanism is neither necessary nor sufficient for the hypertension. However, the combination of alpha- and beta-adrenergic mechanisms maintains cardiac output and peripheral tissue blood flow relatively constant while producing a systemic hypertension.

Control of cardiac output by regional blood flow distribution

1974 ◽  
Vol 2 (2) ◽  
pp. 149-163 ◽  
Author(s):  
Thomas G. Coleman ◽  
R. Davis Manning ◽  
Roger A. Norman ◽  
Arthur C. Guyton
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution

Changes in blood flow distribution during the perinatal period in fetal sheep and lambs

1992 ◽  
Vol 70 (12) ◽  
pp. 1576-1582 ◽  
Author(s):  
Michelle P. Bendeck ◽  
B. Lowell Langille
Keyword(s):  
Blood Flow ◽  
Adrenal Glands ◽  
Flow Distribution ◽  
Perinatal Period ◽  
Tissue Growth ◽  
Late Gestation ◽  
Blood Flow Distribution ◽  
Total Blood ◽  
Fetal Sheep ◽  
Blood Flows

We have measured total blood flows and blood flows per 100 g tissue to major tissues at 120 and 140 days gestation in fetal sheep and at 3 and 21 days of age in lambs (gestation period = 144 ± 2 days). Between 120 and 140 days gestation, flow per 100 g tissue increased by 74, 150, and 317% in the renal, intestinal, and hepatic arterial beds, but no further significant change in flow was observed at 3 or 21 days postpartum. Blood flows per 100 g to cerebral hemispheres and cerebellar tissues also increased dramatically during late gestation (142 and 121%, respectively), but declined sharply by 3 days postpartum (73 and 75%, respectively). Brain blood flows at 21 days postpartum remained substantially below late gestational levels. Adrenal blood flows per 100 g more than doubled during late gestation, fell by more than half at birth, and only partially recovered by 21 days of age. Blood flows to carcass tissues did not change in late gestation, fell at birth, then partially recovered. Pre- and post-natal increases in brain blood flows were almost entirely attributable to increased perfusion rather than tissue growth, whereas large perinatal increases in flow to the diaphragm paralleled tissue growth. Tissue growth and increased perfusion per 100 g contributed almost equally to increased blood flows to kidneys postnatally, and to adrenal glands and the gastrointestinal tract prenatally.Key words: blood flow, perinatal, birth, fetus, sheep.

Influence of simulated microgravity on cardiac output and blood flow distribution during exercise

1995 ◽  
Vol 79 (5) ◽  
pp. 1762-1768 ◽  
Author(s):  
C. R. Woodman ◽  
L. A. Sebastian ◽  
C. M. Tipton
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Aerobic Capacity ◽  
Muscle Blood Flow ◽  
Knee Extensor ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Heavy Exercise ◽  
Cage Control ◽  
Impaired Ability

Rats exposed to simulated conditions of microgravity by head-down suspension (HDS) exhibit reductions in aerobic capacity. This may be due to an impaired ability to augment cardiac output and to redistribute blood flow during exercise. The purpose of this investigation was to measure cardiac output and blood flow distribution in rats that were exposed to 14 days of HDS or cage control conditions. Measurements were obtained at rest and during light-intensity (15 m/min) and heavy-intensity (25 m/min; 10% grade) treadmill exercise. Cardiac output was similar in HDS and cage control rats at rest and light exercise but was significantly lower in HDS rats (-33%) during heavy exercise. Soleus muscle blood flow (ml/min) was lower at rest and during exercise in HDS rats; however, when expressed relative to muscle mass (ml.min-1.100 g-1), soleus blood flow was lower only during light exercise. Plantaris muscle blood flow was lower in HDS rats during heavy exercise. Blood flow to the ankle flexor, knee extensor, and knee flexor muscles was not altered by HDS. Blood flow to the spleen and kidney was significantly higher in HDS rats. It was concluded that the reduction in aerobic capacity associated with HDS is due in part to an impaired ability to augment cardiac output during exercise.

NO supports right ventricular flow dominance and whole body O2 utilization in midgestation fetal lambs

2001 ◽  
Vol 280 (4) ◽  
pp. R1016-R1022 ◽  
Author(s):  
Joseph J. Smolich
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
The Body ◽  
Whole Body ◽  
Blood Flow Distribution ◽  
Blood Flows ◽  
Blood Flow Ratio ◽  
Placental Blood ◽  
Flow Changes ◽  
Placental Blood Flow

It is unknown if nitric oxide (NO) modulates the relative levels of left (LV) and right (RV) ventricular output, fetal O2 consumption, or blood flow distribution between the body and placenta at midgestation. To address these questions, six fetal lambs were instrumented at 89–96 days gestation (term 147 days), and blood flows were measured with radioactive microspheres 3–4 days later at baseline and after inhibition of NO synthesis with 10 mg/kg (l-NNA10) and 25 mg/kg (l-NNA25) N ω-nitro-l-arginine. LV output fell by 74 ± 15 ml · min−1 · kg−1 atl-NNA10 ( P < 0.005), whereas RV output decreased by 90 ± 18 ml · min−1 · kg−1 atl-NNA10 ( P < 0.02) and by a further 80 ± 22 ml · min−1 · kg−1 atl-NNA25 ( P < 0.05). As a result, RV output exceeded LV output at baseline ( P = 0.03) and l-NNA10 ( P < 0.02) but not at l-NNA25. Fetal body blood flow fell by 95 ± 25 ml · min−1 · kg−1 atl-NNA10 ( P < 0.01), but because placental blood flow decreased by 70 ± 22 ml · min−1 · kg−1 atl-NNA10 ( P < 0.01) and a further 71 ± 21 ml · min−1 · kg−1 atl-NNA25 ( P < 0.01), the fetal body-to-placental blood flow ratio was near unity at baseline andl-NNA10 but rose to 1.5 ± 0.3 atl-NNA25 ( P < 0.05). In association with these flow changes, fetal O2 consumption declined by 1.4 ± 0.3 ml · min−1 · kg−1 atl-NNA10 ( P < 0.05) and by a further 1.5 ± 0.6 ml · min−1 · kg−1 atl-NNA25 ( P < 0.02). These findings suggest that, in midgestation fetal lambs, NO supports an RV flow dominance, whole body O2 utilization, and the maintenance of a near-equal fetoplacental blood flow distribution.

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