The aim of the present study was to investigate effects of intravenous (i.v.) choline treatment on serum matrix metalloproteinases (MMP), MMP tissue inhibitors (TIMP) and immunoglobulins (Igs), and to determine if there were relations between serum MMPs/TIMPs and C-reactive protein (CRP) (as a marker of the acute phase response), immunoglobulin G and M (IgG and IgM) (as a maker of the Ig responses) and markers of organ damage such as muscular damage (creatine phosphokinase, [CPK]), liver damage (alanine aminotransferase [ALT]) and renal dysfunction (blood urea nitrogen [BUN] and creatinine, [Cr]) in dogs with endotoxemia. Healthy dogs (n = 24) were randomized to Saline, Choline (C), Lipopolysaccharide (LPS), and LPS + C groups and received 0.9% NaCl (5 mL/i.v.), choline chloride (20 mg/kg/i.v.), LPS (0.02 mg/kg/i.v.) and LPS (0.02 mg/kg/i.v.) plus choline chloride (20 mg/kg/i.v.), respectively. Serum MMPs and TIMPs concentrations were analyzed by commercial ELISA kits. MMP and TIMP increased at 1-48 h (P < 0.05), whereas IgG and IgM decreased at 24-48 h in LPS group, compared to their baselines. Choline treatment reduced changes in serum MMPs, TIMPs and markers of organ damage, and prevented the hypoimmunoglobulinemia in LPS + C. MMPs and TIMPs were correlated positively (P < 0.05) with serum CRP, CPK, ALT, BUN and Cr, but not with serum Igs. Our findings suggest that the serum MMPs, TIMPs and Igs are involved in the pathophysiology of endotoxemia, and MMPs and TIMPs are correlated with the acute phase reaction and multi-organ failure. In addition, we demonstrated a direct effect of choline administration in decreasing serum MMPs and TIMPs, and preserving serum Igs in the course of endotoxemia. (C) 2016 Elsevier B.V. All rights reserved.