Use of para-amino hippuric acid to measure blood flows through portal-drained-viscera, liver and hindquarters in sheep

SUMMARYThe objectives of this study were (i) to evaluate a new surgical procedure to catheterize hepatic vessels as well as the posterior aorta and vena cava, (ii) to test a modification of a downstream dilution technique in order to measure blood flows through splanchnic tissues and hindquarters in rapid succession, and (iii) to improve the reliability of splanchnic blood flow measurements using paraamino hippuric acid (PAH). Ten adult ewes were used. The transhepatic surgical approach used proved successful; it was relatively easy to set up and a good recovery of hepatic functions was obtained. The attempt to measure splanchnic and hindquarters blood flow in rapid succession by alternating the sites of PAH infusion was unsuccessful, probably because of transient modifications in infusion rates due to different blood pressures in veins and arteries. Indeed, arterial PAH concentrations changed with infusion site. Finally, a better reproducibility of splanchnic blood flow measurements was obtained in sheep, fed every 3 h, by infusing the required amount of PAH partly via the mesenteric vein and partly via a ruminal vein.

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Glutamine-enriched enteral diet increases splanchnic blood flow in the rat

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1994.267.6.g1035 ◽

1994 ◽

Vol 267 (6) ◽

pp. G1035-G1040 ◽

Cited By ~ 3

Author(s):

A. P. Houdijk ◽

P. A. Van Leeuwen ◽

M. A. Boermeester ◽

T. Van Lambalgen ◽

T. Teerlink ◽

...

Keyword(s):

Nitric Oxide ◽

Blood Flow ◽

Control Diet ◽

Splanchnic Blood Flow ◽

Systemic Hemodynamic ◽

Flow Measurements ◽

Blood Flows ◽

Fischer 344 ◽

Enteral Diet ◽

Blood Flow Measurements

The hemodynamic consequences of glutamine (Gln)-enriched nutrition have not been investigated. This study investigates the effects of a Gln-enriched enteral diet on organ blood flows and systemic hemodynamics. Male Fischer 344 rats (n = 24) were randomized to a group that received a 12.5% (wt/wt) Gln-enriched enteral diet or an isonitrogenous isocaloric control diet for 14 days. Blood flow measurements were performed at day 16 using 46Sc-labeled microspheres. In the Gln-enriched group, higher organ blood flows were measured in the stomach (51%), the pancreas (35%), small intestine (32%), and colon (55%), compared with controls. No differences were found in systemic hemodynamic parameters between the control and Gln-supplemented groups. A possible role for nitric oxide in this splanchnic vasodilation was investigated. Daily urinary nitrate excretion was measured during the study but showed no significant differences between the control and Gln-fed animals. No differences were found in plasma levels of the vasodilating hormone glucagon between the groups. These results show that a Gln-enriched enteral diet increased splanchnic blood flow, which was not mediated by pancreatic glucagon or increased nitric oxide production as determined by urinary nitrate excretion.

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Pulmonary Blood Flow Measurements Following Vena Cava-to-Pulmonary Artery Anastomosis

The Annals of Thoracic Surgery ◽

10.1016/s0003-4975(10)64945-4 ◽

1973 ◽

Vol 15 (2) ◽

pp. 128-134 ◽

Cited By ~ 5

Author(s):

Francis Robicsek ◽

Walter P. Scott ◽

Norris B. Harbold ◽

Harry K. Daugherty ◽

Donald C. Mullen

Keyword(s):

Blood Flow ◽

Pulmonary Artery ◽

Pulmonary Blood Flow ◽

Vena Cava ◽

Flow Measurements ◽

Blood Flow Measurements

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Variability of splanchnic blood flow measurements in patients with sepsis – physiology, pathophysiology or measurement errors?

Intensive Care Medicine ◽

10.1007/s00134-001-1109-1 ◽

2001 ◽

Vol 27 (11) ◽

pp. 1692-1695 ◽

Cited By ~ 3

Author(s):

S. Jakob ◽

J. Takala

Keyword(s):

Blood Flow ◽

Measurement Errors ◽

Splanchnic Blood Flow ◽

Flow Measurements ◽

Blood Flow Measurements

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The Methodology of Doppler-Derived Central Blood Flow Measurements in Newborn Infants

International Journal of Pediatrics ◽

10.1155/2012/680162 ◽

2012 ◽

Vol 2012 ◽

pp. 1-13 ◽

Cited By ~ 13

Author(s):

Koert A. de Waal

Keyword(s):

Blood Flow ◽

Doppler Ultrasound ◽

Superior Vena ◽

Ductus Arteriosus ◽

Newborn Infants ◽

Vena Cava ◽

Left Ventricular ◽

Flow Measurements ◽

General Guide ◽

Blood Flow Measurements

Central blood flow (CBF) measurements are measurements in and around the heart. It incorporates cardiac output, but also measurements of cardiac input and assessment of intra- and extracardiac shunts. CBF can be measured in the central circulation as right or left ventricular output (RVO or LVO) and/or as cardiac input measured at the superior vena cava (SVC flow). Assessment of shunts incorporates evaluation of the ductus arteriosus and the foramen ovale. This paper describes the methodology of CBF measurements in newborn infants. It provides a brief overview of the evolution of Doppler ultrasound blood flow measurements, basic principles of Doppler ultrasound, and an overview of all used methodology in the literature. A general guide for interpretation and normal values with suggested cutoffs of CBFs are provided for clinical use.

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Fetal placental vascular responses to prostacyclin after angiotensin II-induced vasoconstriction

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1989.257.1.e102 ◽

1989 ◽

Vol 257 (1) ◽

pp. E102-E107

Author(s):

V. M. Parisi ◽

S. W. Walsh

Keyword(s):

Blood Flow ◽

Angiotensin Ii ◽

Vascular Resistance ◽

Control Period ◽

Vena Cava ◽

Ang Ii ◽

Flow Measurements ◽

Control Value ◽

Blood Flow Measurements ◽

Infusion Period

The vasodilator prostacyclin is produced by many fetal tissues and may serve to protect umbilical placental blood flow. We hypothesized that prostacyclin could reverse fetoplacental vasoconstriction produced by angiotensin II (ANG II). Studies were done in eight unanesthetized near-term ovine fetuses. After a control period, ANG II was infused into the fetal inferior vena cava at a rate of 0.5 microgram/min for 40 min. Twenty minutes after starting the ANG II infusion, an infusion of prostacyclin at a rate of 5 micrograms/min was added to the ANG II infusion. Blood flows were measured by the radioactive microsphere technique. Blood flow measurements were made during the control period, 20 min after starting the ANG II infusion, and 20 min after adding prostacyclin to the ANG II infusion. ANG II produced significant fetal hypertension and renal, intestinal, and placental vasoconstriction. Placental vascular resistance rose from 0.14 +/- 0.01 to 0.18 +/- 0.01 mmHg.min.kg fetal wt.ml-1 during the ANG II infusion period (P less than 0.05). The addition of prostacyclin to the ANG II infusion resulted in a return to control values for fetal blood pressure and renal and intestinal resistance. However, placental vasoconstriction was not reversed by addition of prostacyclin as placental vascular resistance remained significantly elevated over the control value (0.17 +/- 0.01 mmHg.min.kg fetal wt.ml-1). Although unchanged by ANG II infusion, fetal pH decreased significantly during the ANG II plus prostacyclin infusion period. We conclude that ANG II causes fetal hypertension and renal and intestinal vasoconstriction, which are reversed by prostacyclin.(ABSTRACT TRUNCATED AT 250 WORDS)

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Time-related changes in microsphere entrapment in canine jejunum

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1989.256.3.g451 ◽

1989 ◽

Vol 256 (3) ◽

pp. G451-G457

Author(s):

I. Prokopiw ◽

P. K. Dinda ◽

I. T. Beck

Keyword(s):

Blood Flow ◽

Muscularis Propria ◽

Fractional Flow ◽

Flow Measurements ◽

Blood Flows ◽

Blood Flow Measurements

To assess the validity of repeated blood flow measurements using the microsphere technique, the apparent blood flows in the anatomic layers of the jejunum were determined from the entrapment of 9-, 11.5-, and 17-micron microspheres at 1.5, 15, 30, and 60 min after their injection. The entrapment of 17-micron spheres in the mucosa plus submucosa and in the muscularis propria remained similar at all times, but these spheres migrated (P less than 0.01) from the submucosa to the mucosa. By 1.5 min, 5 +/- 2% of 11.5-micron spheres had shunted, but no subsequent shunting was observed. No migration of 11.5-micron spheres from the mucosa, submucosa or the muscularis was observed. The shunting of 9-micron spheres from the whole wall increased from 19 +/- 4% at 1.5 min to 40 +/- 4% at 60 min (P less than 0.001). These data suggest that 17-micron spheres can only fractionate the blood flow of the whole wall into that of the mucosa plus submucosa and that of the muscularis propria, while 11.5-micron spheres may measure fractional flow to the submucosa separately. The continued washout of 9-micron microspheres precludes their use for repeated blood flow measurements.

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