Simvastatin reduces reperfusion injury by modulating nitric oxide synthase expression: an ex vivo study in isolated working rat hearts.
OBJECTIVE
We tested the hypothesis of beneficial effects of the 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA)-reductase inhibitor simvastatin in a model of ischemia-reperfusion, and investigated potential mechanisms.


METHODS
Isolated working rat hearts were subjected to 15 min global ischemia and 22-180 min reperfusion in the presence or absence of simvastatin (10-100 microM). We evaluated creatinephosphokinase and nitrite levels in coronary effluent, heart weight changes, microvascular permeability (extravasation of fluoresceine-labeled albumin), ultrastructural alterations, and the expression of endothelial (e) and inducible (i) nitric oxide synthase (NOS) (by reverse-transcribed polymerase chain reaction and Western blotting) in the presence or absence of the transcriptional inhibitor actinomycin-D.


RESULTS
Simvastatin (25 microM) significantly reduced myocardial damage and vascular hyperpermeability, concomitant with a reduction in endothelial and cardiomyocyte lesions. Protection became less evident at 50 microM and reverted to increased damage at 100 microM. At 25 microM, simvastatin significantly increased eNOS mRNA and protein compared with untreated hearts, probably due to a post-transcriptional regulation since unaltered by animal pretreatment with actinomycin D. Simvastatin also significantly decreased iNOS mRNA and protein, as well as nitrite production after ischemia-reperfusion. The addition of the NOS inhibitor N(pi)-nitro-L-arginine methylester (L-NAME, 30 microM) to 25 microM simvastatin-treated hearts significantly reduced cardioprotection against ischemia-reperfusion.


CONCLUSIONS
In this model, in the absence of perfusing granulocytes, the acute administration of a pharmacologically relevant simvastatin concentration reduces ischemia-reperfusion injury and prevents coronary endothelial cell and cardiomyocyte damage by cholesterol-independent, NO-dependent mechanisms.
Di Napoli
P
P
Laboratory of Experimental Cardiology, Department of Clinical Sciences and Bioimaging, "G. d'Annunzio" University of Chieti, Ospedale S. Camillo de Lellis, Via Forlanini, 50, 66100, Chieti, Italy.
Antonio Taccardi
A
A
Grilli
A
A
Spina
R
R
Felaco
M
M
Barsotti
A
A
De Caterina
R
R
D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002199:Capillary Permeability / Q000187:drug effects; D003402:Creatine Kinase / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010477:Perfusion; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D019821:Simvastatin / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects
D004791:Enzyme Inhibitors; D009573:Nitrites; D012333:RNA, Messenger; D019821:Simvastatin; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat; D003402:Creatine Kinase