Regulation of arginase isoforms I and II by IL-4 in cultured murine peritoneal macrophages

A study was conducted to determine the specific arginase isoforms induced by interleukin (IL)-4, a Th2 cytokine shown by others to enhance arginase activity in macrophages, and serum. Findings showed that IL-4, in combination with serum, enhances arginase I, but not arginase II, mRNA in cultured murine macrophages. Also, serum induces both arginase isoforms and is needed for maximal arginase I induction by IL-4.