Pre- and post-sinusoidal origin of hepatic exudate in anesthetized cats

1991 ◽  
Vol 69 (12) ◽  
pp. 1914-1916 ◽  
Author(s):  
C. V. Greenway ◽  
I. R. Innes ◽  
G. D. Scott
Keyword(s):  
Steady State ◽  
Venous Pressure ◽  
Venous Blood ◽  
Portal Blood ◽  
Substantial Part ◽  
Blood Concentrations ◽  
Small Doses ◽  
Hepatic Venous Blood

In cats anesthetized with pentobarbital, hepatic venous pressure was increased to cause drops of exudate to appear on the surface of the liver. These drops were collected during steady-state infusions of small doses of ethanol and galactose when there was a large arteriovenous gradient across the liver. Comparison of the concentrations of these substances in arterial, portal, and hepatic venous blood and exudate showed that the exudate concentrations were slightly higher than the hepatic venous concentrations but markedly lower than arterial and portal blood concentrations. We conclude that the exudate cannot be entirely formed in the space of Mall (presinusoidal) but a substantial part is postsinusoidal in origin. If the exudate is a mixture of fluids equilibrated with inflowing and outflowing blood, then 75–80% of the exudate is postsinusoidal and 20–25% is presinusoidal in origin.Key words: lymph, ascites, galactose, ethanol.

Changes in hepatic blood volume on galactose and indocyanine green uptake by cat liver

1989 ◽  
Vol 256 (3) ◽  
pp. G524-G531 ◽  
Author(s):  
C. V. Greenway ◽  
I. R. Innes ◽  
K. L. Pushka ◽  
G. D. Scott ◽  
D. S. Sitar
Keyword(s):  
Indocyanine Green ◽  
Blood Volume ◽  
Venous Pressure ◽  
Venous Blood ◽  
Galactose Metabolism ◽  
Blood Concentrations ◽  
Hepatic Congestion ◽  
Hepatic Venous Blood ◽  
Repeated Sampling ◽  
Mild Impairment

The liver has important functions as a blood volume reserve and in uptake and metabolism of many substrates. This study examines whether changes in hepatic blood volume modify the uptakes of model substrates galactose and indocyanine green (ICG) in cats anesthetized with pentobarbital sodium. A hepatic venous long-circuit technique with an extracorporeal reservoir was used to control hepatic flow and venous pressure and to allow repeated sampling of arterial, portal, and hepatic venous blood without depletion of the cat's blood volume. Hepatic blood volume was measured by plethysmography. Galactose and ICG were infused intravenously at constant rates for 200 min in each of three series of experiments. The first series were time controls. In the second series, hepatic blood volume was increased by raising hepatic venous pressure. In the third series hepatic blood volume was decreased by hepatic nerve stimulation and infusions of norepinephrine and angiotensin. Hepatic congestion resulted in small increases in blood galactose levels, suggesting mild impairment of hepatic galactose metabolism. Decreases in liver blood volume did not modify hepatic galactose metabolism. Increases in hepatic blood volume facilitated while decreases inhibited ICG uptake, but the effects were small. Sinusoidal velocity and transit time have minor effects on uptake even for protein-bound substrates. In summary, large changes in hepatic blood volume had minor effects on galactose and ICG blood concentrations, suggesting that the metabolic functions of the liver are essentially independent of the blood reservoir function.

Pharmacokinetics and Arteriovenous Differences in Clevidipine Concentration following a Short- and a Long-term Intravenous Infusion in Healthy Volunteers

2000 ◽  
Vol 92 (4) ◽  
pp. 993-1001 ◽  
Author(s):  
Hans Ericsson ◽  
Ulf Bredberg ◽  
Ulf Eriksson ◽  
Åse Jolin-Mellgård ◽  
Margareta Nordlander ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Steady State ◽  
Healthy Volunteers ◽  
Venous Blood ◽  
Volume Of Distribution ◽  
Pharmacokinetic Parameters ◽  
Blood Levels ◽  
Blood Concentrations ◽  
Arterial Blood ◽  
The Mean

Background Clevidipine is an ultra-short-acting calcium antagonist developed for reduction and control of blood pressure during cardiac surgery. The objectives of the current study were to determine the pharmacokinetics of clevidipine after 20-min and 24-h intravenous infusions, and to determine the relation between the arterial and venous concentrations and the hemodynamic responses to clevidipine in healthy volunteers. Methods Four volunteers received clevidipine for 20 min, and eight subjects were administered clevidipine intravenously for 24 h at two different dose rates. Arterial and venous blood samples were drawn for pharmacokinetic evaluation, and blood pressure and heart rate were recorded. Results A triexponential disposition model described the pharmacokinetics of clevidipine. The mean arterial blood clearance of clevidipine was 0.069l/kg-1/min-1 and the mean volume of distribution at steady state was 0.19 l/kg. The duration of the infusion had negligible effect on the pharmacokinetic parameters, and the context-sensitive half-time for clevidipine, simulated from the mean pharmacokinetic parameters derived after 24 h infusion at the highest dose, was less than 1 min. The arterial blood levels reached steady state within 2 min of the start of infusion and were about twice as high as those in the venous blood at steady state. The peak response preceded the peak venous concentration and was slightly delayed from the peak arterial blood concentration. Conclusion Clevidipine is a high clearance drug with a small volume of distribution, resulting in extremely short half-lives in healthy subjects. The initial rapid increase in the arterial blood concentrations and the short equilibrium time between the blood and the biophase suggest that clevidipine can be rapidly titrated to the desired effect.

Neural activation of α-adrenoreceptors in glucose mobilization from liver

1979 ◽  
Vol 57 (9) ◽  
pp. 1037-1039 ◽  
Author(s):  
W. Wayne Lautt
Keyword(s):  
Nerve Stimulation ◽  
Adrenergic Receptors ◽  
Venous Pressure ◽  
Portal Pressure ◽  
Venous Blood ◽  
Pressure Change ◽  
Neural Activation ◽  
Parasympathetic Nerve ◽  
Hepatic Venous Blood ◽  
Glucose Output

Using a newly described method for obtaining pure, mixed hepatic venous blood samples, it was demonstrated that glucose mobilization from the liver of the anesthetized cat in response to hepatic nerve stimulation is via α-adrenergic receptors. Neither the elevation of portal pressure nor the amount of glucose generated by the liver was affected by intraportal administration of 1 mg propranolol/kg (β blockade). In the presence of α-receptor blockade (3 mg phentolamine/kg) the portal venous pressure change was minor and the glucose output actually decreased slightly upon nerve stimulation, a response consistent with our previously demonstrated reduction of glucose output by parasympathetic nerve stimulation. The present responses to nerve stimulation were not due to activation of pancreatic nerves since these nerves were routinely ligated.

Modification of lymph by lymph nodes. II. Effect of increased lymph node venous blood pressure

1983 ◽  
Vol 245 (4) ◽  
pp. H616-H622 ◽  
Author(s):  
T. H. Adair ◽  
A. C. Guyton
Keyword(s):  
Blood Pressure ◽  
Lymph Node ◽  
Steady State ◽  
Lymph Nodes ◽  
Flow Rate ◽  
Protein Concentration ◽  
Venous Pressure ◽  
Venous Blood ◽  
Free Fluid ◽  
Fluid Exchange

A previous study from this laboratory demonstrated that lymph nodes can change the protein concentration and colloid osmotic pressure of lymph by transfer of protein-free fluid between the blood and lymph compartments. In that study a Starling force disequilibrium across the blood-lymph barrier caused fluid to transfer through the barrier in the direction required to establish equilibrium of Starling forces. In the present study we examined the effect of increased lymph node venous blood pressure on efferent lymph protein concentration and efferent lymph flow. We utilized an isolated dog popliteal lymph node preparation in which afferent lymph having various protein concentrations was perfused into the node at an average flow rate of 19.1 +/- 0.3 (SD) microliter/min. We compared steady-state values of prenodal and postnodal lymph flows and protein concentrations during various steady-state levels of lymph node venous blood pressure. When venous pressure was increased, the protein concentration of the efferent lymph invariably decreased and the efferent flow rate invariably increased. Measurements showed that an average of 96% of the change in lymph protein concentration was caused by transfer of protein-free fluid through the lymph node blood-lymph barrier. The results of this study indicate again that the lymph node functions as a fluid exchange chamber in which fluid is transferred between the blood and lymph compartments in the direction required to establish equilibrium of the Starling forces across the blood-lymph barrier.

Relationship between hepatic venous anatomy and hepatic venous blood loss during hepatectomy

Surgery Today ◽  
2021 ◽  
Author(s):  
Atsushi Nanashima ◽  
Yukinori Tanoue ◽  
Tatefumi Sakae ◽  
Isao Tsuneyoshi ◽  
Masahide Hiyoshi ◽  
...  
Keyword(s):  
Blood Loss ◽  
Venous Blood ◽  
Venous Anatomy ◽  
Hepatic Venous Blood ◽  
Hepatic Venous Anatomy

Off-pump direct hepatic veins-to-hemiazygos vein anastomosis after primary Kawashima operation: long-term result

2021 ◽  
pp. 1-3
Author(s):  
Renate Kaulitz ◽  
Gerhard Ziemer ◽  
Michael Hofbeck
Keyword(s):  
Venous Blood ◽  
Venous Drainage ◽  
Hepatic Veins ◽  
Off Pump ◽  
Hemiazygos Vein ◽  
Close Proximity ◽  
Hepatic Venous Blood ◽  
Balanced Distribution ◽  
Long Term Result

Abstract Direct hepatic veins-to-hemiazygos connection offers the balanced distribution of hepatic venous blood to both lungs, not requiring anticoagulation. We report a 13-year follow-up after this type of off-pump Fontan completion. Patient’s hepatic veins-to-hemiazygos confluence increased with growth to allow for unobstructed flow. This unique technique can be recommended in heterotaxy patients, if atrial hepatic venous drainage and hemiazygos vein are in close proximity.

scholarly journals The Position of Central Venous Catheters Inserted through Arm Veins: A Preliminary Report

1974 ◽  
Vol 2 (1) ◽  
pp. 43-47 ◽  
Author(s):  
D. G. Woods ◽  
Jean Lumley ◽  
W. J. Russell ◽  
R. D. Jack
Keyword(s):  
Preliminary Report ◽  
Heart Surgery ◽  
Venous Pressure ◽  
Venous Blood ◽  
Open Heart Surgery ◽  
Central Venous Catheters ◽  
Open Heart ◽  
Central Venous ◽  
Central Venous Blood ◽  
Catheter Tip

Fifty-three central venous catheters were followed up by radiography or direct observation during open-heart surgery. Forty of these were satisfactorily positioned for recording central venous pressure or for sampling central venous blood. Radiography showed that the catheter tip was in an unsatisfactory position in 21 per cent of cases. It is recommended that radiographic confirmation of the site of the catheter tip be obtained as a routine and if necessary the catheter can be re-positioned and another radiograph taken.

Branched-Chain Amino Acids, Nitrogen Excretion and Injury in Man

1976 ◽  
Vol 50 (5) ◽  
pp. 393-399 ◽  
Author(s):  
J. H. Wedge ◽  
R. De Campos ◽  
A. Kerr ◽  
R. Smith ◽  
Rose Farrell ◽  
...  
Keyword(s):  
Amino Acids ◽  
Venous Blood ◽  
Branched Chain Amino Acids ◽  
Nitrogen Excretion ◽  
Adult Males ◽  
Blood Concentrations ◽  
Branched Chain ◽  
Injured Patients ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

1. Venous blood concentrations of the branched-chain amino acids, valine, leucine and isoleucine, and urinary nitrogen excretion have been measured in sixteen adult males, from 2 h to 7 days after injury, and in four adults after elective skin grafts. 2. In the injured group the concentrations of these amino acids rose significantly 24 h after injury and had doubled at 4 days and remained high; in contrast the skin-graft patients showed no significant change. 3. In those injured patients with initial hyperketonaemia, defined as more than 0·2 mmol/l, the increase in concentrations of branched-chain amino acids at the fourth and seventh days after injury was significantly less than in those with normoketonaemia, and was accompanied by lower urinary nitrogen excretion throughout the whole period. 4. It is suggested that the changes in the concentration of branched-chain amino acids after injury indicate decreased uptake by muscle or excessive release due to an imbalance between protein synthesis and protein catabolism in this tissue.

Semiparametric approach to pharmacokinetic-pharmacodynamic data

1989 ◽  
Vol 256 (4) ◽  
pp. R1005-R1010
Author(s):  
D. Verotta ◽  
S. L. Beal ◽  
L. B. Sheiner
Keyword(s):  
Steady State ◽  
Rate Constant ◽  
Drug Concentration ◽  
Venous Blood ◽  
Time Lag ◽  
Elimination Rate ◽  
Hysteresis Loops ◽  
Real Data ◽  
Elimination Rate Constant ◽  
Arterial Blood

A semiparametric model for analysis of pharmacokinetic (PK) and pharmacodynamic (PD) data arising from non-steady-state experiments is presented. The model describes time lag between drug concentration in a sampling compartment, e.g., venous blood (Cv), and drug effect (E). If drug concentration at the effect site (Ce) equilibrates with arterial blood concentration (Ca) slower than with Cv, a non-steady-state experiment yields E vs. Cv data describing a counterclockwise hysteresis loop. If Ce equilibrates with Ca faster than with Cv, clockwise hysteresis is observed. To model hysteresis, a parametric model is proposed linking (unobserved) Ca to Cv with elimination rate constant kappa ov and also linking Ca to Ce with elimination rate constant kappa oe. When kappa oe is greater than (or less than) kappa ov clockwise (or counterclockwise) hysteresis occurs. Given kappa oe and kappa ov, numerical (constrained) deconvolution is used to obtain the disposition function of the arterial compartment (Ha), and convolution is used to calculate Ce given Ha. The values of kappa oe and kappa ov are chosen to collapse the hysteresis loops to single curves representing the Ce-E (steady-state) concentration-response curve. Simulations, and an application to real data, are reported.

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