The hydrogen sulphide-releasing derivative of diclofenac protects against ischaemia-reperfusion injury in the isolated rabbit heart.
OBJECTIVE
Hydrogen sulphide (H(2)S) is an endogenous gaseous mediator active in the multilevel regulation of pathophysiological functions in mammalian cardiovascular tissues.


METHODS
This study investigated the pharmacological activity of a new H(2)S-releasing derivative of diclofenac, S-diclofenac (2-[(2,6-dichlorophenyl)amino]benzeneacetic acid 4-(3H-1,2-dithiole-3-thione-5-yl)-phenyl ester) in the isolated rabbit heart submitted to low-flow ischaemia-reperfusion damage.


RESULTS
S-diclofenac (3, 10 and 30 microM), despite inhibiting prostacyclin generation by cardiac tissues, achieved dose-dependent normalization of coronary perfusion pressure, reducing left ventricular contracture during ischaemia and improving left ventricular developed pressure and +/-dP/dt(max) at reperfusion. Creatine kinase and lactate dehydrogenase activities in heart perfusates were significantly reduced during reperfusion. These effects were accompanied by substantial release of reduced glutathione (GSH), indicating that the H(2)S moiety may have up-regulated cysteine transport. The anti-ischaemic activities of S-diclofenac and the H(2)S-donor sodium hydro sulphide (NaHS) were partially prevented by the K(ATP) channel antagonist glibenclamide, suggesting a mechanism similar to H(2)S-induced cardioprotection in metabolic ischaemic preconditioning. Perfusion with the nitric oxide (NO) synthase inhibitor N(G)-monomethyl-L-arginine worsened the myocardial ischaemia-reperfusion damage, but this was dose-dependently prevented by S-diclofenac and NaHS, suggesting that the released H(2)S may have overcome NO deficiency.


CONCLUSIONS
These data show that S-diclofenac had marked anti-ischaemic activity in ischaemic-reperfused rabbit hearts despite inhibition of prostaglandin generation. Increased GSH formation leading to activation of K(ATP) channels may have contributed to this beneficial effect. The pharmacological profile of S-diclofenac and its anti-inflammatory activity, with diminished gastrointestinal side effects, offer therapeutic applications in cardiovascular disease.
Rossoni
G
G
Department of Pharmacology, Chemotherapy and Medical Toxicology, University of Milan, Milan, Italy. giuseppe.rossoni@unimi.it
Sparatore
A
A
Tazzari
V
V
Manfredi
B
B
Del Soldato
P
P
Berti
F
F
D000818:Animals; D003402:Creatine Kinase / Q000097:blood; D004008:Diclofenac / Q000031:analogs & derivatives* / Q000494:pharmacology; D011464:Epoprostenol / Q000096:biosynthesis; D005978:Glutathione / Q000378:metabolism; D005905:Glyburide / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D006862:Hydrogen Sulfide / Q000378:metabolism*; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011817:Rabbits; D013440:Sulfides / Q000494:pharmacology; D013871:Thiones / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects
C520611:2-((2,6-dichlorophenyl)amino)benzeneacetic acid 4-(3H-1,2-dithiol-3-thione-5-yl)phenyl ester; D013440:Sulfides; D013871:Thiones; D004008:Diclofenac; D009569:Nitric Oxide; D011464:Epoprostenol; D007770:L-Lactate Dehydrogenase; D019001:Nitric Oxide Synthase; D003402:Creatine Kinase; C025451:sodium bisulfide; D005978:Glutathione; D005905:Glyburide; D006862:Hydrogen Sulfide