Effect of liver blood flow and function on hepatic indocyanine green clearance measured directly in a cirrhotic animal model

2000 ◽  
Vol 87 (12) ◽  
pp. 1734-1735 ◽  
Author(s):  
D. V. Mann ◽  
A. K. K. Chui ◽  
W. Y. Lau
1988 ◽  
Vol 66 (5) ◽  
pp. 592-595 ◽  
Author(s):  
Patrick R. Montgomery ◽  
Daniel S. Sitar

Liver blood flow and hepatic uptake of some indicator substances have been reported to fall with age in both rats and humans. We used an isolated liver system, which was perfused in one pass with hemoglobin free buffer, to investigate the effect of albumin concentration, buffer flow rate, and age upon hepatic clearance of the dye, indocyanine green. We measured the half-life of a bolus of indocyanine green given intravenously to male Sprague–Dawley rats aged 10 and 24 months and then examined its clearance in vitro using their isolated perfused livers. After perfusion, the livers were homogenized and separated into subcellular fractions. The mean liver weight declined significantly (young, 19.7 ± 2.9 g vs. old, 13.9 ± 2.6 g; p < 0.02). In vivo the indocyanine green clearance was reduced in the aged rats (3.2 ± 1.0 vs. 5.1 ± 1.7 mL/min; p < 0.05). In the isolated perfused liver system, extraction ratio showed an inverse curvilinear correlation with albumin concentration and buffer flow rate, but did not differ with age. Hepatic protein content and dye subcellular localization did not differ between the two groups. In conclusion, the fall in indocyanine green clearance in vivo is not paralleled by the ability of the organs to extract the dye in vitro, and likely reflects a decline in hepatic mass and blood flow.


1989 ◽  
Vol 76 (5) ◽  
pp. 503-508 ◽  
Author(s):  
E. Burns ◽  
C. E. Ball ◽  
J. P. Christie ◽  
G. D. Broadhead ◽  
G. T. Tucker ◽  
...  

1. In order to estimate liver blood flow in the rat, the extraction ratio of Indocyanine Green was determined using a two-compartment model fitted to the plasma concentration time data after a single intravenous bolus dose and compared with values obtained directly by transhepatic sampling, both in the intact rat and in an isolated perfused rat liver preparation. 2. There was no agreement between estimates of the extraction ratio obtained by using the kinetic model and the directly measured values. 3. Elimination curves for Indocyanine Green were simulated to yield varied clearance values. Despite a 250% variation in clearance, extraction ratios derived using the two-compartment model were all greater than 0.9 and varied by less than 6%. 4. Estimates of liver blood flow obtained by deriving a value of the extraction ratio of Indocyanine Green using the two-compartment model are inaccurate.


1994 ◽  
Vol 86 (5) ◽  
pp. 497-503 ◽  
Author(s):  
J. Burggraaf ◽  
H. C. Schoemaker ◽  
J. M. Kroon ◽  
L. Huisman ◽  
C. Kluft ◽  
...  

1. Endogenous fibrinolytic capacity increases after administration of 1-desamino-8-d-vasopressin. This increase is commonly attributed to an increase in release of tissue-type plasminogen activator from the endothelium. However, the possibility that 1-desamino-8-d-vasopressin influences liver blood flow, which is a major determinant of tissue-type plasminogen activator clearance, cannot be ruled out. 2. The influence of 1-desamino-8-d-vasopressin on haemodynamics, liver blood flow and fibrinolytic parameters was investigated in a randomized double-blind cross-over study in nine healthy male subjects (age 20–26 years). 3. 1-Desamino-8-d-vasopressin exerted significant haemodynamic effects: mean arterial pressure decreased maximally 12 (95% confidence interval 8–15) mmHg and heart rate increased maximally 21 (95% confidence interval 15–27) beats/min. 4. Endogenous fibrinolytic parameters increased after administration of 1-desamino-8-d-vasopressin. Both tissue-type plasminogen activator antigen and tissue-type plasminogen activator activity were elevated and showed the maximal response shortly after drug administration was completed. 5. 1-Desamino-8-d-vasopressin increased portal venous blood flow as measured with echo-Doppler. The maximal increase in mean blood flow of 55 (95% confidence interval 19–92)% was observed at the end of the 1-desamino-8-d-vasopressin infusion and coincided with the maximal changes in systemic haemodynamics and fibrinolytic parameters. The increase in portal blood flow was not reflected in significant changes in Indocyanine Green clearance. It appears that the Indocyanine Green method is relatively insensitive to increases in liver blood flow. 6. The observed increase in fibrinolytic activity due to tissue-type plasminogen activator activity after 1-desamino-8-d-vasopressin administration may be due to an increased release of tissue-type plasminogen activator from the endothelium and is not caused by changes in clearance.


Perfusion ◽  
1999 ◽  
Vol 14 (1) ◽  
pp. 29-36 ◽  
Author(s):  
D AC Sharpe ◽  
I M Mitchel ◽  
E A Kay ◽  
J P McGoldrick ◽  
C M Munsch ◽  
...  

Liver blood flow is reduced after cardiopulmonary bypass (CPB) and both dopamine and dopexamine are used to overcome this. This study compares the effects of these agents on liver blood flow. Thirty patients undergoing elective coronary artery bypass graft surgery were randomized into three groups ( n = 10 per group). Six hours after surgery baseline liver blood flow was determined by the percentage disappearance rate of indocyanine green measured by dichromatic auricular densitometery. Patients then received infusions of either: (1) placebo (dextrose 5%); (2) dopamine (4 μg/kg/min); (3) dopexamine (1 μg/kg/min increasing to 2 μg/kg/min). One hour after infusion, liver blood flow measurements were repeated. In the dopexamine group the infusion was increased and the measurements repeated another hour later. We found that patient-specific variables and operative details were similar for all groups. Postoperative cardiac index and heart rate were increased significantly by dopamine (cardiac index 2.82 ± 0.46 l/m/m2 vs 3.28 ± 0.67 l/m/m2: p < 0.001 and heart rate 87.5 ± 13.2 vs 96 ± 16: p < 0.05) and dopexamine at 2 μg/kg/min (cardiac index 2.71 ± 0.53 l/m/m2 vs 3.45 ± 0.67 l/m/m2: p < 0.05 and heart rate 89.0 ± 18.9 vs 107.4 ± 13.6: p < 0.001) compared to placebo (cardiac index 2.97 ± 0.8 l/m/m2 vs 3.18 ± 0.9 l/m/m2: p > 0.05 and heart rate 77.2 ± 7.4 vs 77.3 ± 8: p > 0.05) despite similar atrial and systemic arterial pressures. The disappearance rate of indocyanine green was not altered during infusion of placebo group (9.0 ± 3.2%/min vs 7.9 ± 3.0%/min: p > 0.05) or dopexamine at 1 μg/kg/min (9.7 ± 3.1%/min vs 11.2 ± 4.1%/min: p > 0.05). The disappearance rate was increased with dopamine (6.7 ± 3.7%/min vs 11.8 ± 3.0%/min: p < 0.05) and dopexamine 2 μg/kg/min (9.7 ± 3.1%/min vs 13.5 ± 3.2%/min: p < 0.05). This indicates a 76% increase in liver blood flow with dopamine and a 38% increase with dopexamine. We conclude that dopamine 4 μg/kg/min and dopexamine 2 μg/kg/min increase liver blood flow, although this may, in part, be related to an increase in cardiac output. Dopexamine shows no advantage over dopamine in enhancing liver blood flow after CPB.


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