Hepatic ischemia/reperfusion affects leukocyte rolling and velocity

Area of Science:

• Hepatology
• Immunology
• Vascular Biology

Background:

• Hepatic ischemia/reperfusion (I/R) injury mechanisms are not fully understood.
• Leukocytes are implicated in the final stages of liver damage during I/R injury.
• Quantifying leukocyte kinetics is crucial for understanding I/R injury.

Purpose of the Study:

• To investigate the time course of abnormal leukocyte activity in the liver post-I/R injury.
• To characterize changes in leukocyte rolling, saltation, and velocity in the liver after I/R.
• To establish a quantifiable measure of leukocyte kinetics in hepatic I/R.

Main Methods:

• Induction of 20-minute left lobar hepatic ischemia in C57B1-6 mice.
• Measurements of leukocyte kinetics using rhodamine and fluorescein enhanced intravital microscopy.
• Evaluation of post-sinusoidal venules at 2, 5, 12, and 24 hours post-reperfusion and sham controls.

Main Results:

• Significantly increased numbers of rolling leukocytes observed at 5, 12, and 24 hours of reperfusion (p < 0.001).
• Significantly slower leukocyte velocities noted in the 12-hour I/R group compared to sham animals (p < 0.001).
• Quantifiable and definable changes in leukocyte kinetics persisted for up to 24 hours post-I/R.

Conclusions:

• Hepatic I/R injury causes sustained, quantifiable alterations in leukocyte kinetics.
• These leukocyte changes are likely mediated by the upregulation of endothelial cell adhesion molecules.
• Understanding these mechanisms is vital for treating conditions like shock, sepsis, and in liver transplantation.