MMP-2 Plays an Important Role During the Early Acute Developmental Phase of Oligofructose-Induced Equine Laminitis

The study was conducted on 24 Mongolian horses, with oligofructose-induced equine laminitis (10 g/kg b.w.). The objective of the study was to investigate the relationships among matrix metalloproteinase 2 (MMP-2), P38 mitogen-activated protein kinases (P38 MAPK), tissue inhibitor of metalloproteinase 2 (TIMP-2), lipopolysaccharides (LPS), and tumour necrosis factor-α (TNF-α) during acute developmental phase of laminitis, and to determine whether there are any characteristic tendencies. Moreover, plasma concentrations of LPS and TNF-α were measured in order to determine the time of leukocytes’ activation. Eleven of the 12 horses showed clinical signs of laminitis. The contents of MMP-2 and P38 MAPK increased significantly from 8 h to 64 h, and the content of TIMP-2 decreased significantly at the same time. Plasma LPS concentrations increased significantly between 8 h and 20 h and reached a peak of 0.024 ± 0.009 EU/mL (equivalent to 3.04 ± 1.19 pg/mL) at 12 h. TNF-α concentration increased between 20 h and 36 h. This data indicates that MMP-2 plays an important role during the early acute developmental phase of oligofructose-induced equine laminitis.