Hepatic uptake of indocyanine green and perfusion rate in rats: effect of age and albumin concentration

1988 ◽  
Vol 66 (5) ◽  
pp. 592-595 ◽  
Author(s):  
Patrick R. Montgomery ◽  
Daniel S. Sitar
Keyword(s):  
Blood Flow ◽  
Indocyanine Green ◽  
Flow Rate ◽  
Liver Blood Flow ◽  
Hepatic Uptake ◽  
Albumin Concentration ◽  
Sprague Dawley ◽  
Indocyanine Green Clearance

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.

scholarly journals P2X1 receptor blockade inhibits whole kidney autoregulation of renal blood flow in vivo

2010 ◽  
Vol 298 (6) ◽  
pp. F1360-F1368 ◽  
Author(s):  
David A. Osmond ◽  
Edward W. Inscho
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Perfusion ◽  
Receptor Activation ◽  
Receptor Blockade ◽  
Sprague Dawley ◽  
Receptor Stimulation ◽  
Kidney Blood Flow

In vitro experiments demonstrate that P2X1 receptor activation is important for normal afferent arteriolar autoregulatory behavior, but direct in vivo evidence for this relationship occurring in the whole kidney is unavailable. Experiments were performed to test the hypothesis that P2X1 receptors are important for autoregulation of whole kidney blood flow. Renal blood flow (RBF) was measured in anesthetized male Sprague-Dawley rats before and during P2 receptor blockade with PPADS, P2X1 receptor blockade with IP5I, or A1 receptor blockade with DPCPX. Both P2X1 and A1 receptor stimulation with α,β-methylene ATP and CPA, respectively, caused dose-dependent decreases in RBF. Administration of either PPADS or IP5I significantly blocked P2X1 receptor stimulation. Likewise, administration of DPCPX significantly blocked A1 receptor activation to CPA. Autoregulatory behavior was assessed by measuring RBF responses to reductions in renal perfusion pressure. In vehicle-infused rats, as pressure was decreased from 120 to 100 mmHg, there was no decrease in RBF. However, in either PPADS- or IP5I-infused rats, each decrease in pressure resulted in a significant decrease in RBF, demonstrating loss of autoregulatory ability. In DPCPX-infused rats, reductions in pressure did not cause significant reductions in RBF over the pressure range of 100–120 mmHg, but the autoregulatory curve tended to be steeper than vehicle-infused rats over the range of 80–100 mmHg, suggesting that A1 receptors may influence RBF at lower pressures. These findings are consistent with in vitro data from afferent arterioles and support the hypothesis that P2X1 receptor activation is important for whole kidney autoregulation in vivo.

Hepatic uptake and biliary excretion of Indocyanine green and its use in estimation of hepatic blood flow in dogs

1960 ◽  
Vol 199 (3) ◽  
pp. 481-484 ◽  
Author(s):  
Sigmund G. Ketterer ◽  
Bernard D. Wiegand ◽  
Elliot Rapaport
Keyword(s):  
Blood Flow ◽  
Indocyanine Green ◽  
Plasma Volume ◽  
Biliary Excretion ◽  
Liver Blood Flow ◽  
Hepatic Function ◽  
Volume Of Distribution ◽  
Hepatic Uptake ◽  
Constant Infusion ◽  
Volume Recovery

Indocyanine green when injected intravenously into normal dogs rapidly disappears, after mixing, from the circulation in an initial exponential fashion. This property enables one to calculate its original volume of distribution and its clearance from the circulation. The initial volume of distribution corresponded closely with the circulating plasma volume. Recovery of the dye from surgically created biliary fistulas approached 100% of the injected amounts and averaged 91%. During constant infusion, significant hepatic arteriovenous differences in dye concentrations occurred, making it possible to calculate hepatic clearances, extraction ratios and liver blood flow. The values obtained by the latter method agreed well with those obtained following single injections. The virtually complete hepatic uptake of Indocyanine green, ease of quantitative plasma and biliary determinations and its exponential loss from the circulation with a short half-life provide advantages over previously used substances in evaluating hepatic function and blood flow.

Glutamine blocks lipolysis and ketogenesis of fasting

1986 ◽  
Vol 250 (3) ◽  
pp. E248-E252 ◽  
Author(s):  
E. Cersosimo ◽  
P. Williams ◽  
B. Hoxworth ◽  
W. Lacy ◽  
N. Abumrad
Keyword(s):  
Fatty Acids ◽  
Blood Flow ◽  
Metabolic Acidosis ◽  
Indocyanine Green ◽  
Plasma Insulin ◽  
Hepatic Uptake ◽  
In Vivo Studies ◽  
Portal Veins ◽  
Beta Hydroxybutyrate

Several in vivo studies have indirectly suggested a relationship between blood glutamine and ketonemia. The present study was designed to characterize the role glutamine plays in regulating lipolysis and ketogenesis during fasting in vivo. Twelve dogs had catheters implanted in the hepatic and portal veins (V) and in the femoral artery (A) 17-21 days before study. The animals were fasted for 4 days. After a 120-min rest and 40-min basal periods, 6 dogs received an infusion of L-glutamine at 6 mumol X kg-1 X min-1 and 6 received saline and acted as controls. Hepatic and splanchnic balances (mumol X kg-1 X min-1) were estimated by A-V differences multiplied by blood flow determined by indocyanine green. Fasting was associated with a compensated (no change in pH) mild metabolic acidosis but no change in plasma insulin and glucagon or blood glutamine. L-Glutamine infusion increased blood glutamine by 20% but decreased arterial free fatty acids (FFA, from 1,054 +/- 47 to 850 +/- 43 mumol/l, P less than 0.01), beta-hydroxybutyrate (beta-OHB, from 136 +/- 15 to 66 +/- 8 mumol/l, P less than 0.01), acetoacetate (AcAc, from 168 +/- 26 to 86 +/- 21 mumol/l, P less than 0.01), and glycerol (from 90 +/- 4 to 65 +/- 5 mumol/l, P less than 0.01). It also decreased hepatic uptake of glycerol (from 2.5 +/- 0.5 to 0.8 +/- 0.3 mumol X kg-1 X min-1, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

Effect of caffeine on theophyliine on cerebral blood flow response to brain activation: In vitro and in vivo studies

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S198-S198
Author(s):  
Joseph R Meno ◽  
Thien-son K Nguyen ◽  
Elise M Jensen ◽  
G Alexander West ◽  
Leonid Groysman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Activation ◽  
In Vivo Studies ◽  
Blood Flow Response ◽  
Flow Response
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