Effect of increased cardiac output on liver blood flow, oxygen exchange and metabolic rate during longterm endotoxin-induced shock in pigs

Starvation results in an energy-conserving reduction in metabolic rate that has features of an adaptive response. Tissue and organ sites of this response were investigated by examining the effects of starvation for 5 d on tissue blood flow (microsphere method) and regional arteriovenous O2 differences [Formula: see text] in conscious rats resting quietly at 28 °C. Comparison was with fed and overnight-fasted animals. Whole body resting metabolic rates (MR), colonic temperatures (Tc), and tissue weights were also determined. Quantitative changes in energy expenditure (as O2 consumption) were obtained for two regions: the portal-drained viscera (PDV) and the hindquarters (HQ). Fasting overnight resulted in increased blood flow to white adipose tissue (WAT) and decreased flow to the brain, PDV, testes, and skin; however, MR, Tc, the two regional [Formula: see text], and the weights of most tissues were not significantly altered. In comparison with overnight fasting, starvation for 5 d resulted in a 13% reduction in body weight, weight loss in many tissues and organs, a 26% reduction in MR, a decline of 0.5 °C in Tc, decreased [Formula: see text] across both the PDV and HQ, reduced cardiac output, and decreased blood flow to the heart, PDV, skin, WAT, leg muscle, HQ, and the musculoskeletal body as a whole. Utilization of O2 by the PDV and HQ [Formula: see text] declined by amounts that accounted for 22 and 18%, respectively, of the reduction in MR. The reductions in cardiac output (18%) and heart blood flow (36%) indicate that the heart also made a contribution to energy conservation (roughly estimated as 5%). Overall, the data suggest that gut and muscle together accounted for two-thirds to three-quarters of the starvation-induced energy conservation.

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EFFECTS OF VASODILATOR DRUGS AND OTHER PROCEDURES ON DIGITAL CUTANEOUS BLOOD FLOW, CARDIAC OUTPUT, BLOOD PRESSURE, PULSE RATE, BODY TEMPERATURE, AND METABOLIC RATE

The American Journal of the Medical Sciences ◽

10.1097/00000441-194921860-00009 ◽

1949 ◽

Vol 218 (6) ◽

pp. 669-682 ◽

Cited By ~ 35

Author(s):

Orville Horwitz ◽

Hugh Montgomery ◽

Edwin Downs Longaker ◽

Ann Saÿen

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Cardiac Output ◽

Body Temperature ◽

Metabolic Rate ◽

Pulse Rate ◽

Pressure Pulse ◽

Cutaneous Blood Flow ◽

Vasodilator Drugs ◽

Cutaneous Blood

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Effects of hemorrhage on umbilical venous return and oxygen delivery in fetal lambs

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1982.242.4.h543 ◽

1982 ◽

Vol 242 (4) ◽

pp. H543-H548 ◽

Cited By ~ 1

Author(s):

J. Itskovitz ◽

B. W. Goetzman ◽

A. M. Rudolph

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Oxygen Delivery ◽

Venous Return ◽

Liver Blood Flow ◽

Ductus Venosus ◽

Organ Blood Flow ◽

Acute Hemorrhage ◽

Arterial Circulation ◽

Fetal Organs

The effect of acute hemorrhage (21.7 +/- 1.6%, mean +/- SE of the estimated blood volume) on the distribution of the umbilical venous return (UVR) and oxygen delivery to fetal organs (radionuclide microsphere technique) was studied in 10 chronically catheterized fetal lambs. Hemorrhage decreased UVR and total oxygen delivery to the fetus by 23 and 28%, respectively (P less than 0.001). A greater proportion of the UVR bypassed the liver through the ductus venosus (DV) (P less than 0.01). Consequently, DV blood flow was relatively maintained, and liver blood flow and oxygen delivery derived from the UVR decreased by 41 and 45%, respectively (P less than 0.002). The proportion of cardiac output constituted by DV blood increased by 30% (P less than 0.01). The changes in the distribution of the DV blood were similar to the changes in the distribution of cardiac output. As a result the proportion of organ blood flow and oxygen delivery derived from DV blood increased by 30% in both the upper and lower body organs. These studies show that fetal hemorrhage has a marked effect on the distribution of the UVR to the liver. The preferential distribution of the DV blood to the heart and brain is maintained but not enhanced. Our results indicate that changes in distribution of the DV-derived blood and oxygen following fetal hemorrhage is determined primarily by the responses of the arterial circulation, i.e., circulatory afterload.

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Respiratory, cardiovascular, and metabolic adjustments to hypoxemia during sleep in piglets

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y98-088 ◽

1998 ◽

Vol 76 (7-8) ◽

pp. 747-755 ◽

Cited By ~ 10

Author(s):

Aurore Côté ◽

Hernan Porras

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Metabolic Rate ◽

Breathing Pattern ◽

Ventilatory Response ◽

Cardiovascular Response ◽

Regional Distribution ◽

Moderate Degree ◽

Active Sleep ◽

Output Measurement

The influence of sleep on ventilation, metabolic rate, cardiovascular function, and regional distribution of blood flow during hypoxemia (PaO2 of 45-50 mmHg (1 mmHg = 133.3 Pa)) was studied in piglets at 6 ± 1 and 34 ± 5 days (mean ± SD). Measurement of ventilation and metabolic rate was done in a metabolic chamber, and blood flow was measured using the microsphere technique. A subgroup of animals was instrumented for cardiac output measurement (dye-dilution technique) and continuous monitoring of the hemoglobin saturation in oxygen (SaO2) We found that although sleep did not influence the metabolic and cardiac output response to hypoxemia, it affected the ventilatory response as well as the brain and the respiratory muscle blood flows. During active sleep in the older animals, the ventilatory response to hypoxemia was smaller than in the other two states; marked drops in SaO2 occurred with changes in the breathing pattern; and that state was associated with the highest rate of brain blood flow. As well, age affected the ventilatory and metabolic response, but not the cardiovascular response to hypoxemia. The age-dependent ventilatory changes with hypoxemia (smaller ventilatory response in the young than in the older animals) were related to the different levels of oxygen consumption. In summary, active sleep was responsible for all the sleep-dependent changes in the response to a moderate degree of hypoxemia.Key words: breathing pattern, metabolic rate, blood flow, microspheres, maturation.

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Liver Blood Flow as a Major Determinant of the Clearance of Recombinant Human Tissue-Type Plasminogen Activator

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648385 ◽

1992 ◽

Vol 67 (01) ◽

pp. 083-087 ◽

Cited By ~ 44

Author(s):

A de Boer ◽

C Kluft ◽

J M Kroon ◽

F J Kasper ◽

H C Schoemaker ◽

...

Keyword(s):

Blood Flow ◽

Rat Liver ◽

Healthy Subjects ◽

Liver Blood Flow ◽

Major Determinant ◽

Tissue Type ◽

Perfused Rat Liver ◽

Liver Model ◽

Type Plasminogen Activator ◽

Proportional Change

SummaryThe influence of changes in liver blood flow on the clearance of rt-PA was studied both in healthy subjects and in a perfused rat liver model. Liver blood flow in healthy subjects was documented indirectly by the clearance of indocyanine green (ICG). Exercise reduced liver blood flow on average by 57% with a 95% confidence interval (95% Cl) ranging from 51% to 62% (n = 5) and increased plasma levels of rt-PA activity (after an i. v. infusion of 18 mg of rt-PA over 120 min) by 119% (95% Cl, 58% - 203%) and rt-PA antigen by 91% (95% Cl, 30% - 140%). In the perfused rat liver model it was shown that halving or doubling of the physiological flow rate of a perfusate, containing rt-PA caused a proportional change in the clearance of rt-PA, while the extraction of rt-PA by the liver remained similar. In conclusion, liver blood flow is a major determinant of the clearance of rt-PA. This may have important implications for dosage of rt-PA in patients with myocardial infarction.

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