title: Plasma matrix metalloproteinase activity in horses after intravenous infusion of lipopolysaccharide and treatment with matrix metalloproteinase inhibitors.
abstract: OBJECTIVE
  To establish an in vivo method for matrix metalloproteinase (MMP)-2 and MMP-9 induction in horses via IV administration of lipopolysaccharide (LPS) and to evaluate the ability of doxycycline, oxytetracycline, flunixin meglumine, and pentoxifylline to inhibit equine MMP-2 and MMP-9 production.
  
  
  METHODS
  29 adult horses of various ages and breeds and either sex.
  
  
  METHODS
  In part 1, horses received an IV administration of LPS (n = 5) or saline (0.9% NaCl) solution (5). Venous blood samples were collected before and at specified times for 24 hours after infusion. Plasma was harvested and analyzed for MMP-2 and MMP-9 activities via zymography. In part 2, horses received doxycycline (n = 5), oxytetracycline (5), flunixin meglumine (5), or pentoxifylline (4) before and for up to 12 hours after administration of LPS. Plasma was obtained and analyzed, and results were compared with results from the LPS-infused horses of part 1.
  
  
  RESULTS
  Administration of LPS significantly increased MMP-2 and MMP-9 activities in the venous circulation of horses. All MMP inhibitors significantly decreased LPS-induced increases in MMP activities but to differing degrees. Pentoxifylline and oxytetracycline appeared to be the most effective MMP-2 and MMP-9 inhibitors, whereas doxycycline and flunixin meglumine were more effective at inhibiting MMP-2 activity than MMP-9 activity.
  
  
  CONCLUSIONS
  IV administration of LPS to horses caused increased venous plasma activities of MMP-2 and MMP-9. These MMP activities were reduced by pentoxifylline and oxytetracycline, suggesting that further evaluation of these medications for treatment and prevention of MMP-associated diseases in horses is indicated.
authors: Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. lfugler@tigers.lsu.edu
authors: Lee Ann
authors: LA
authors: Fugler
authors: Susan C
authors: SC
authors: Eades
authors: Rustin M
authors: RM
authors: Moore
authors: Catherine E
authors: CE
authors: Koch
authors: Michael L
authors: ML
authors: Keowen
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D003002:Clonixin / Q000031:analogs & derivatives / Q000494:pharmacology; D004318:Doxycycline / Q000494:pharmacology; D019446:Endotoxemia / Q000201:enzymology / Q000662:veterinary*; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006736:Horses / Q000097:blood*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000097:blood*; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000097:blood*; D010118:Oxytetracycline / Q000494:pharmacology; D010431:Pentoxifylline / Q000494:pharmacology; D011897:Random Allocation; D056152:Respiratory Rate / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; C014558:flunixin meglumine; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D004318:Doxycycline; D010431:Pentoxifylline; D003002:Clonixin; D010118:Oxytetracycline