Elevated plasma arginase-1 does not affect plasma arginine in patients undergoing liver resection. Academic Article uri icon

abstract

  • Arginine is an important substrate in health and disease. It is a commonly held view that arginase-1 release from injured erythrocytes and hepatocytes leads to arginine breakdown; however, the true relationship between plasma arginase-1 concentration and activity has remained unaddressed. In the present study, blood was sampled from patients undergoing liver resection, a known cause of hepatocyte injury and arginase-1 release, to determine arginase-1, arginine and ornithine plasma levels. Arginase activity was assessed in vitro by measuring changes in arginine and ornithine plasma levels during incubation of plasma and whole-blood samples at 37 degrees C. Arginase-1 plasma levels increased 8-10-fold during liver resection, whereas arginine and ornithine levels remained unchanged. In accordance with these in vivo findings, arginine and ornithine levels remained unchanged in plasma incubated at 37 degrees C irrespective of the arginase-1 concentration. In contrast, arginine plasma levels in whole blood decreased significantly during incubation, with ornithine increasing stoichiometrically. These changes were irrespective of arginase-1 plasma levels and were explained by arginase activity present in intact erythrocytes. Next, plasma samples with 1000-fold normal arginase-1 concentrations were obtained from patients undergoing cadaveric liver transplantation. A significant decrease in arginine plasma levels occurred in vivo and in vitro. In contrast with commonly held views, moderately increased arginase-1 plasma levels do not affect plasma arginine. Very high plasma arginase-1 levels are required to induce potential clinically relevant effects.

published proceedings

  • Clin Sci (Lond)

author list (cited authors)

  • van de Poll, M., Hanssen, S., Berbe, M., Deutz, N., Monbaliu, D., Buurman, W. A., & Dejong, C.

citation count

  • 14

complete list of authors

  • van de Poll, Marcel CG||Hanssen, Sebastiaan JP||BerbĂ©e, Maaike||Deutz, Nicolaas EP||Monbaliu, Diethard||Buurman, Wim A||Dejong, Cornelis HC

publication date

  • February 2008