High plasma levels of arginine and liver arginase in Kupffer-cell-depletedrats after partial hepatectomy

Background/Aims: The remnant liver after partial hepatectomy releases argin ase into the plasma, which is a reliable indicator of hepatocellular damage . Little information is available on how this release affects arginine plas ma levels. We hypothesized that Kupffer cells after partial hepatectomy may prevent further hepatocellular damage, contributing to lower arginase rele ase. The aim of the study was to evaluate the role of Kupffer cells in plas ma arginase activity and arginine plasma levels after partial hepatectomy. Methods: Wag/Rij rats (n=72, 250-275 g) were randomly assigned to receive 1 mi liposome-encapsulated dichloromethylene-diphosphonate in order to elimi nate Kupffer cells (DMDP, n=24), 1 mi liposome encapsulated-phosphate buffe red saline (PBS, n=24) or 1 mi NaCl 0.9% (NaCl, n=24) intravenously. Forty- eight hours later, all rats had a two-third liver resection. Rats were kill ed at 0, 24, 48 and 96 h after partial hepatectomy. Results: Arginase plasma activity was higher in the DMDP-treated group comp ared to NaCl and PBS (both p<0.01, p<0.05, p<0.01 and p<0.05 for 0, 24, 48 and 96 h after partial hepatectomy respectively). Arginine plasma levels in creased, but were lower in the DMDP group compared to NaCl and PBS (both p< 0.05, 24 h after hepatectomy). Conclusion: The study showed that Kupffer cell depletion results in a highe r arginase release from the remnant liver after partial hepatectomy, indica ting a hepatocellular protective function of Kupffer cells. Despite this ar ginase release, arginine plasma levels were increased after partial hepatec tomy.