Interpretation of the Laser Doppler Flow Signal from the Liver of the Rat

Wheatley, Anthony M.; Almond, N. E.; Stuart, Edward T.; Zhao, Delai

doi:10.1006/mvre.1993.1025

Cited by 55 publications

(39 citation statements)

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“…22 Its use for measurement of the HM has been validated in animal models. 22,23 Parenchymal perfusion measured by LDF correlates well with total liver blood flow, and surface LDF measurements are representative of deep parenchymal perfusion. 24,25 In human liver studies perfusion measurements by LDF were found to be reproducible with a coefficient of variation of 4%.…”

Section: Measurement Of Liver Blood Flow and The Hmmentioning

confidence: 84%

The effect of mechanically enhancing portal venous inflow on hepatic oxygenation, microcirculation, and function in a rabbit model with extensive hepatic fibrosis

et al. 1999

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Enhancing the portal venous blood flow (PVBF) has been shown to reduce portal pressure and intrahepatic vascular resistance and to improve liver function in isolated cirrhotic rodent livers in vitro. The aim of this study was to assess the short-term effect of mechanically pumping the portal inflow on hepatic microcirculation (HM), oxygenation, and function in an animal model of extensive hepatic fibrosis. New Zealand white rabbits underwent laparotomy and exposure of the liver: group 1 (n ‫؍‬ 7) were normal controls; group 2 (n ‫؍‬ 7) had hepatic fibrosis. Total hepatic blood flow (THBF) and HM was measured along with continuous monitoring of intrahepatic tissue oxygenation using near infrared spectroscopy (NIRS). Baseline hepatic hemodynamics and liver function were measured in both groups. PVBF was then increased by 50% over a 3-hour period in the hepatic fibrosis group using a miniature portal pump designed for human implantation, and the hemodynamics were monitored continuously. Liver function tests were repeated after portal pumping. In comparison with normal controls, animals with hepatic fibrosis had a higher portal pressure (13.0 ؎ 3.6 vs. 3.7 ؎ 1.4 mm Hg, P F .001, mean ؎ SD vs. controls), reduced PVBF (52.4 ؎ 24.6 vs. 96.9 ؎ 21.1 mL/min, P ‫؍‬ .003), and increased portal vascular resistance (P ‫؍‬ .001). THBF and flow in the HM was lower than in controls, and liver function tests were abnormal. After a 3-hour period of enhanced portal flow in animals with hepatic fibrosis, the portal pressure greatly reduced (13.0 ؎ 3.6 to 2.5 ؎ 1.1 mm Hg, P F .001) as did the intrahepatic portal resistance ( Current aims in the management of portal hypertension are to reduce portal venous pressure (PVP), to increase blood flow through hepatic parenchyma, 1 and to decompress esophageal and gastric varices. 2,3 Reduction of PVP minimizes the risk of bleeding from varices, the likelihood of hepatic encephalopathy and problems relating to first pass uptake of drugs. 4 Reduced portal pressure also decreases intestinal venous congestion and could increase blood flow through the hepatic parenchyma and hence increase liver function. 5 In 1991, Habib et al. 6 first introduced the concept of mechanical pumping of portal blood to enhance hepatic portal inflow. Since then, we have seen a number of publications in this field. 7-10 Cardoso et al. [7][8][9] showed that augmenting portal inflow to isolated perfused cirrhotic rat and human livers decreased intrahepatic resistance without a change in intrahepatic shunting and resulted in liver function improvement. Bernadich et al. 10 found that in rats with portal hypertension owing to portal vein stenosis, mechanical portal pumping decreased portal pressure and portal-systemic shunting without having a significant effect on systemic hemodynamics. In cirrhosis, several early studies provided evidence that it was vasoactive mediators coupled with the extensive destruction of hepatocytes and nodular regeneration that contributed to the pathogenesis of portal hypertension. [11][12][13]...

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Section: Measurement Of Liver Blood Flow and The Hmmentioning

confidence: 84%

The effect of mechanically enhancing portal venous inflow on hepatic oxygenation, microcirculation, and function in a rabbit model with extensive hepatic fibrosis

et al. 1999

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“…Figure 3 shows changes in MABP and TIFP as a function of time after an i.p. injection of 100 mg kg-' PTX (n = 13 (Wheatley et al, 1993).…”

Section: Resultsmentioning

confidence: 99%

Changes in tumour blood flow, oxygenation and interstitial fluid pressure induced by pentoxifylline

Lee

Boucher²,

Demhartner³

et al. 1994

Br J Cancer

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“…A microprobe (P5a/ P5b) was placed on the surface of the left lobe of the livers. The LDF signal is digitized with Moor Lab software (Moor Instruments) and sinusoidal blood flow was expressed in arbitrary units (Wheatley et al, 1993).…”

Section: Laser Doppler Flowmetermentioning

confidence: 99%

Age-related changes in the hepatic microcirculation in mice

Yoshiya

Sørensen

Bethea

et al. 2007

Experimental Gerontology

113

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Aging of the liver is associated with impaired metabolism of drugs, adverse drug interactions, and susceptibility to toxins. Since reduced hepatic blood flow is suspected to contribute this impairment, we examined age-related alterations in hepatic microcirculation.. Livers of C57Bl/6 mice were examined at 0.8 (pre-pubertal), 3 (young adult), 14 (middle-aged) and 27 (senescent) months of age using in vivo and electron microscopic methods. The results demonstrated a 14% reduction in the numbers of perfused sinusoids between 0.8 and 27 month mice associated with 35% reduction in sinusoidal blood flow. This was accompanied by an inflammatory response evidenced by a 5-fold increase in leukocyte adhesion in 27 month mice, up-regulated expression of ICAM-1, and increases in intrahepatic macrophages. Sinusoidal diameter decreased 6-10%. Liver sinusoidal endothelial cell (LSEC) dysfunction was seen as early as 14 months when there was a 3-fold increase in the numbers of swollen LSEC. The endocytotic capacity of LSEC also was found to be reduced in older animals. The sinusoidal endothelium in 27 month old mice exhibited pseudocapillarization. In conclusion, the results suggest that leukocyte accumulation in the sinusoids and narrowing of sinusoidal lumens due to pseudocapillarization and dysfunction of LSEC reduce sinusoidal blood flow in aged livers.

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Interpretation of the Laser Doppler Flow Signal from the Liver of the Rat

Cited by 55 publications

References 0 publications

The effect of mechanically enhancing portal venous inflow on hepatic oxygenation, microcirculation, and function in a rabbit model with extensive hepatic fibrosis

The effect of mechanically enhancing portal venous inflow on hepatic oxygenation, microcirculation, and function in a rabbit model with extensive hepatic fibrosis

Changes in tumour blood flow, oxygenation and interstitial fluid pressure induced by pentoxifylline

Age-related changes in the hepatic microcirculation in mice

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