Intravital multiphoton microscopy can model uptake and excretion of fluorescein in hepatic ischemia-reperfusion injury

• Published in: Journal of biomedical optics Vol. 18; no. 10; p. 101306
• Main Authors: Thorling, Camilla A, Liu, Xin, Burczynski, Frank J, Fletcher, Linda M, Roberts, Michael S, Sanchez, Washington Y
• Format: Journal Article
• Language: English
• Published: United States Society of Photo-Optical Instrumentation Engineers 01-10-2013
• Subjects: Alanine Transaminase - blood; Angiogenic Proteins - analysis; Angiogenic Proteins - genetics; Angiogenic Proteins - metabolism; Animals; ATP-Binding Cassette Transporters - analysis; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Blotting, Western; Chromatography, High Pressure Liquid; Excretion; Fluorescein; Fluorescein - analysis; Fluorescein - chemistry; Fluorescein - pharmacokinetics; Histocytochemistry; Image Processing, Computer-Assisted - methods; Imaging; Injuries; Liver; Liver - blood supply; Liver - chemistry; Liver - metabolism; Male; Mathematical models; Microscopy, Fluorescence, Multiphoton - methods; Organic Anion Transporters - analysis; Organic Anion Transporters - genetics; Organic Anion Transporters - metabolism; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Reperfusion Injury - metabolism; Tomography; Uptakes; ischemia-reperfusion injury; biliary excretion; multiphoton microscopy; real-time polymerase chain reaction; drug transport; high-performance liquid chromatography; western blot; intravital imaging
• ISSN: 1083-3668; 1560-2281
• DOI: 10.1117/1.JBO.18.10.101306

The liver is important in the biotransformation of various drugs, where hepatic transporters facilitate uptake and excretion. Ischemia-reperfusion (I/R) injury is a common occurrence in liver surgery, and the developing oxidative stress can lead to graft failure. We used intravital multiphoton tomography, with fluorescence lifetime imaging, to characterize metabolic damage associated with hepatic I/R injury and to model the distribution of fluorescein as a measure of liver function. In addition to measuring a significant increase in serum alanine transaminase levels, characteristic of hepatic I/R injury, a decrease in the averaged weighted lifetime of reduced nicotinamide adenine dinucleotide phosphate was observed, which can be attributed to a changed metabolic redox state of the hepatocytes. I/R injury was associated with delayed uptake and excretion of fluorescein and elevated area-under-the-curve within the hepatocytes compared to sham (i.e., untreated control) as visualized and modeled using images recorded by intravital multiphoton tomography. High-performance liquid chromatography analysis showed no differences in plasma or bile concentrations of fluorescein. Finally, altered fluorescein distribution was associated with acute changes in the expression of liver transport proteins. In summary, multiphoton intravital imaging is an effective approach to measure liver function and is more sensitive in contrasting the impact of I/R injury than measuring plasma and bile concentrations of fluorescein.