GASTROINTESTINAL BLOOD FLOW DISTRIBUTION IN COLD-EXPOSED SHEEP

1980 ◽  
Vol 60 (3) ◽  
pp. 677-681 ◽  
Author(s):  
A. L. SCHAEFER ◽  
B. A. YOUNG
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Gastrointestinal Tract ◽  
Cold Exposure ◽  
Flow Distribution ◽  
Treatment Groups ◽  
Acute Cold Exposure ◽  
Control Versus ◽  
Gastrointestinal Blood Flow ◽  
Distribution Of Cardiac Output

The influence of acute and chronic cold exposure on the distribution of cardiac output to the gastrointestinal tract was measured in adult sheep (35–50 kg) using radioactive microspheres containing 141Ce and 113Sn. Groups of four sheep were exposed in controlled temperature chambers to either (1) control temperature, 18 °C for 10–12 wk; (2) acute cold, exposure to 3 °C for 12 h; (3) chronic cold, exposure to 3 °C for 10–12 wk. In the control, acute cold and chronic cold treatments, respectively, 26.4, 20.5 and 19.4% of cardiac output was distributed to the gastrointestinal tract. The estimated amount of blood flow (mL/100 g wet tissue/min) to the total gastrointestinal tract was not significantly different among the three treatment groups (67 mL/100 g/min for the control versus 62 and 50 mL/100 g/min, respectively, for the acute cold and the chronic cold sheep). However, there was a significant decrease in blood flow to the reticulo-rumen of the acute cold- and chronic cold-exposed sheep (34.0 and 37.8 mL/100 g wet tissue/min for the acute and chronic cold sheep versus 56.0 mL/100 g/min for the control sheep). The redistribution of gastrointestinal blood flow induced by exposure to cold may be a factor in reduced nutrient absorption in cold-exposed ruminants.

DISTRIBUTION OF BLOOD FLOW IN COLD STRESSED PIGLETS

1979 ◽  
Vol 59 (4) ◽  
pp. 721-726 ◽  
Author(s):  
P. E. V. WILLIAMS ◽  
R. O. PARKER ◽  
B. A. YOUNG ◽  
F. X. AHERNE
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cold Stress ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Alimentary Tract ◽  
Distribution Of Cardiac Output

Radioactive ruthenium labelled microspheres 15 ± 3 μm in diameter were used to determine distribution of cardiac output in unfed control (35 °C) and unfed cold stressed (5 °C) piglets 3.5 h of age. The cold stress produced an average 7.1 °C drop in rectal temperature and a redistribution of blood flow. In cold exposed piglets the adrenal fraction of cardiac output was significantly (P < 0.05) lower: 0.56% in the control compared with 0.29% in the cold exposed piglets; however, the relative blood flow to the adrenals was higher than for other tissues. The fractions of cardiac output reaching the psoas and biceps muscles increased (P < 0.05) by 148 and 260%, respectively, during cold exposure, while that reaching the heart, brain, alimentary tract, skin and fat was not significantly (P > 0.05) affected by cold exposure.

Gastrointestinal tract O2 uptake and regional blood flows during digestion in conscious newborn lambs

1981 ◽  
Vol 241 (4) ◽  
pp. G289-G293 ◽  
Author(s):  
D. I. Eldelstone ◽  
I. R. Holzman
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Whole Body ◽  
O2 Uptake ◽  
Blood Flows ◽  
O2 Extraction ◽  
Regional Blood Flows ◽  
Gastrointestinal Blood Flow

We determined gastrointestinal tract O2 uptake, cardiac output, regional blood flows, and whole-body O2 uptake before and for 1-6 h after feeding in 10 chronically catheterized unanesthetized lambs (9-15 days of age). Total gastrointestinal blood flow (sum of blood flows to the stomach, small intestine, and colon, as calculated with the radioactive microsphere technique) increased 23% at 1 h postprandially. This increased flow at 1 h was due to a large increase in blood flow to the stomach, whereas blood flows to the small intestine and colon did not change significantly. By 2 h, stomach blood flow and thus total gastrointestinal blood flow had returned to fasting values. In contrast, total O2 uptake by the gastrointestinal tract organs (stomach, small intestine, and colon) increased 65% at 1 h, 51% at 2 h, and 28% at 3 h postprandially in association with increases in O2 extraction (O2 uptake/O2 delivery) of 41% at 1 h, 45% at 2 h, and 27% at 3 h. There were no digestion-related changes in whole-body O2 uptake or in cardiac output and its distribution to the brain, heart, kidney, liver (hepatic artery), and carcass. Our data indicate that postprandial increases in O2 demand by gastrointestinal tract organs of the newborn animal are met primarily by enhanced tissue O2 extraction, rather than by metabolic hyperemia, because the postprandial hyperemia observed in the neonate is of short duration and is confined to the stomach.

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.

Gastrointestinal blood flow and oxygen consumption in awake newborn piglets: effect of feeding

1983 ◽  
Vol 245 (5) ◽  
pp. G697-G702 ◽  
Author(s):  
P. T. Nowicki ◽  
B. S. Stonestreet ◽  
N. B. Hansen ◽  
A. C. Yao ◽  
W. Oh
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
O2 Consumption ◽  
Gi Tract ◽  
Local Blood Flow ◽  
O2 Uptake ◽  
O2 Extraction ◽  
Gastrointestinal Blood Flow ◽  
O2 Delivery ◽  
Effect Of Feeding

Regional and total gastrointestinal (GI) blood flow, O2 delivery, and whole-gut O2 extraction and O2 consumption were measured before and 30, 60, and 120 min after feeding in nonanesthetized, awake 2-day-old piglets. Cardiac output and blood flow to kidneys, heart, brain, and liver were also determined. Blood flow was measured using the radiolabeled microsphere technique. In the preprandial condition, total GI blood flow was 106 +/- 9 ml X min-1 X 100 g-1, while O2 extraction was 17.2 +/- 0.9% and O2 consumption was 1.99 +/- 0.19 ml O2 X min-1 X 100 g-1. Thirty minutes after slow gavage feeding with 30 ml/kg artificial pig milk, O2 delivery to the GI tract and O2 extraction rose significantly (P less than 0.05) by 35 +/- 2 and 33 +/- 2%, respectively. The increase in O2 delivery was effected by a significant increase in GI blood flow, which was localized to the mucosal-submucosal layer of the small intestine. O2 uptake by the GI tract increased 72 +/- 4% 30 min after feeding. Cardiac output and blood flow to non-GI organs did not change significantly with feeding, whereas arterial hepatic blood flow decreased significantly 60 and 120 min after feeding. The piglet GI tract thus meets the oxidative demands of digestion and absorption by increasing local blood flow and tissue O2 extraction.

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

Circulatory effects of acute or chronic endotoxemia in rats

1981 ◽  
Vol 59 (2) ◽  
pp. 204-208 ◽  
Author(s):  
R. Keeler ◽  
Anamaria Barrientos ◽  
K. Lee
Keyword(s):  
Escherichia Coli ◽  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Gastrointestinal Tract ◽  
Peripheral Resistance ◽  
Circulatory Effects ◽  
Arterial Blood ◽  
Flow Changes ◽  
Fractional Distribution

A study was made of the effects of acute (4 h) or chronic (4 days) infusion of Escherichia coli endotoxin on cardiovascular function in rats. Rats with acute endotoxemia had a reduced cardiac output but maintained their arterial blood pressure. Fractional distribution of the cardiac output was increased to the liver and reduced to the gastrointestinal tract and skin. No changes in fractional distribution to the kidneys, lungs, or heart were observed although absolute blood flow to these areas was reduced.Rats with chronic endotoxemia had a reduced cardiac output and hypotension with no change in peripheral resistance. Other changes resembled those seen in acute endotoxemia apart from a low renal fraction of the cardiac output. Calculation and interpretation of blood flow changes in these animals was difficult because of a large fall in hematocrit and changes in organ weight.

Distribution of cardiac output during induced isometric exercise in dogs

1979 ◽  
Vol 236 (2) ◽  
pp. H218-H224 ◽  
Author(s):  
S. C. Crayton ◽  
R. Aung-Din ◽  
D. E. Fixler ◽  
J. H. Mitchell
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Adrenergic Receptor ◽  
Isometric Exercise ◽  
Peripheral Resistance ◽  
Minute Volume ◽  
Adrenergic Blockade ◽  
Limb Muscles ◽  
Anesthetized Dogs ◽  
Distribution Of Cardiac Output

Studies were designed to characterize the distribution of cardiac output during induced isometric exercise in anesthetized dogs. The response to isometric exercise involved significant increases in heart rate (+12 +/- 3%(SE)), mean arterial pressure (+13 +/- 2%), cardiac output (+26 +/- 8%), and respiratory minute volume (+75 +/- 26%); total peripheral resistance did not change significantly. Significant changes in blood flow were observed during isometric exercise in kidneys (-18 +/- 6%) and contracting limb muscles (+453 +/- 154%). Flow to liver (hepatic artery), spleen, brain, and myocardium remained near control values. Section of spinal dorsal roots L6-L7 abolished the responses to isometric exercise except for the increase in flow to exercising limb muscles. Alpha-adrenergic receptor blockade abolished the decrease in renal blood flow during isometric exercise; however, the increase in flow to exercising limb muscles was not affected by either alpha- or beta-adrenergic blockade.

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