Postischemic poly (ADP-ribose) polymerase (PARP) inhibition reduces ischemia reperfusion injury in a hind-limb ischemia model.
BACKGROUND
Several experiments were designed to determine whether the systemic, postischemic administration of PJ34,which is a poly-adenosine diphosphate (ADP)-ribose polymerase inhibitor, decreased tissue injury and inflammation after hind-limb ischemia reperfusion (I/R).


METHODS
C57BL6 mouse limbs were subjected to 1.5 h ischemia followed by 24-h reperfusion. The treatment group (PJ) received intraperitoneal PJ34 (30 mg/kg) immediately before reperfusion, as well as 15 min and 2 h into reperfusion. The control group (CG) received lactated Ringer's alone at the same time intervals as PJ34 administration. The skeletal muscle levels of adenosine triphosphate (ATP), macrophage inflammatory protein-2 (MIP-2), keratinocyte derived chemokine (KC), and myeloperoxidase (MPO) were measured. Quantitative measurement of skeletal muscle tissue injury was assessed by microscopic analysis of fiber injury.


RESULTS
ATP levels were higher in limbs of PJ versus CG mice (absolute ATP: 4.7 +/- 0.35 vs 2.3 +/- 0.15-ng/mg tissue, P = .002). The levels of MIP-2, KC, and MPO were lower in PJ versus CG mice (MIP-2: 1.4 +/- 0.34 vs 3.67 +/- 0.67-pg/mg protein, P = .014; KC: 4.97 +/- 0.97 vs 12.65 +/- 3.05-pg/mg protein, P = .037; MPO: 46.27 +/- 10.53 vs 107.34 +/- 13.58-ng/mg protein, P = .008). Muscle fiber injury was markedly reduced in PJ versus CG mice (4.25 +/- 1.9% vs 22.68 +/- 3.0% total fibers, P = .0004).


CONCLUSIONS
Systemic postischemic administration of PJ34 preserved skeletal muscle energy levels, decreased inflammatory markers, and preserved tissue viability post-I/R. These results support PARP inhibition as a viable treatment for skeletal muscle I/R in a clinically relevant post hoc scenario.
Crawford
Robert S
RS
Division of Vascular and Endovascular Surgery, Massachusetts General Hospital, Boston, MA 02114, USA.
Albadawi
Hassan
H
Atkins
Marvin D
MD
Jones
John E
JE
Yoo
Hyung-Jin
HJ
Conrad
Mark F
MF
Austen
W Gerald
WG
Watkins
Michael T
MT
D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D054360:Chemokine CXCL1 / Q000032:analysis; D054426:Chemokine CXCL2 / Q000032:analysis; D004195:Disease Models, Animal; D006614:Hindlimb; D007511:Ischemia / Q000188:drug therapy* / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000737:chemistry / Q000473:pathology; D010616:Phenanthrenes / Q000494:pharmacology; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D015427:Reperfusion Injury / Q000517:prevention & control*
D054360:Chemokine CXCL1; D054426:Chemokine CXCL2; C475895:Cxcl1 protein, mouse; C404915:Cxcl2 protein, mouse; C434926:N-(oxo-5,6-dihydrophenanthridin-2-yl)-N,N-dimethylacetamide hydrochloride; D010616:Phenanthrenes; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D000255:Adenosine Triphosphate