Poloxamer 188 protects against ischemia-reperfusion injury in a murine hind-limb model.
BACKGROUND
Ischemia-reperfusion injury can activate pathways generating reactive oxygen species, which can injure cells by creating holes in the cell membranes. Copolymer surfactants such as poloxamer 188 are capable of sealing defects in cell membranes. The authors postulated that a single-dose administration of poloxamer 188 would decrease skeletal myocyte injury and mortality following ischemia-reperfusion injury.


METHODS
Mice underwent normothermic hind-limb ischemia for 2 hours. Animals were treated with 150 microl of poloxamer 188 or dextran at three time points: (1) 10 minutes before ischemia; (2) 10 minutes before reperfusion; and (3) 2 or 4 hours after reperfusion. After 24 hours of reperfusion, tissues were analyzed for myocyte injury (histology) and metabolic dysfunction (muscle adenosine 5'-triphosphate). Additional groups of mice were followed for 7 days to assess mortality.


RESULTS
When poloxamer 188 treatment was administered 10 minutes before ischemia, injury was reduced by 84 percent, from 50 percent injury in the dextran group to 8 percent injury in the poloxamer 188 group (p < 0.001). When administered 10 minutes before reperfusion, poloxamer 188 animals demonstrated a 60 percent reduction in injury compared with dextran controls (12 percent versus 29 percent). Treatment at 2 hours, but not at 4 hours, postinjury prevented substantial myocyte injury. Preservation of muscle adenosine 5'-triphosphate paralleled the decrease in myocyte injury in poloxamer 188-treated animals. Poloxamer 188 treatment significantly reduced mortality following injury (10 minutes before, 75 percent versus 25 percent survival, p = 0.0077; 2 hours after, 50 percent versus 8 percent survival, p = 0.032).


CONCLUSIONS
Poloxamer 188 administered to animals decreased myocyte injury, preserved tissue adenosine 5'-triphosphate levels, and improved survival following hind-limb ischemia-reperfusion injury.
Murphy
Adrian D
AD
Boston, Mass.; and Chicago, Ill. From the Divisions of Plastic and Reconstructive Surgery and Vascular and Endovascular Surgery, Massachusetts General Hospital, Harvard Medical School; and the Departments of Surgery, Medicine, Organismal Biology, and Anatomy, Committee on Molecular Medicine, University of Chicago.
McCormack
Michael C
MC
Bichara
David A
DA
Nguyen
John T
JT
Randolph
Mark A
MA
Watkins
Michael T
MT
Lee
Raphael C
RC
Austen
William G
WG
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003911:Dextrans / Q000494:pharmacology; D004195:Disease Models, Animal; D006614:Hindlimb / Q000098:blood supply / Q000378:metabolism / Q000473:pathology*; D019194:Ischemic Preconditioning / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D020442:Poloxamer / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015427:Reperfusion Injury / Q000401:mortality / Q000473:pathology* / Q000517:prevention & control*; D013501:Surface-Active Agents / Q000494:pharmacology*
D003911:Dextrans; D017382:Reactive Oxygen Species; D013501:Surface-Active Agents; D020442:Poloxamer; D000255:Adenosine Triphosphate