IL6 and peritonitis: In the current study, parenteral-fed rats with nonlethal, sub-acute peritonitis (i.e., the CPP group) did not show significant changes in the plasma concentrations of TNF-α, IL-6, IFN-γ, and IL-2, the numbers of circulating WBCs and splenocytes, or the subpopulations of leukocytes and splenocytes compared to parenteral-fed rats with a sham operation (i.e., the TPN group).