Nitroglycerin-induced direct protection of the ischaemic myocardium in isolated working hearts of rats with vascular tolerance to nitroglycerin.
We investigated whether nitroglycerin (NTG) was able to produce an anti-ischaemic effect in isolated working hearts of rats with vascular tolerance to NTG. Hearts isolated from tolerant and non-tolerant rats were subjected to 10 min coronary occlusion in the presence of 10(-7) M NTG and/or its solvent. NTG alleviated ischaemia-induced deterioration of cardiac function and decreased lactate dehydrogenase release whilst having no effect on coronary flow nor the area of the ischaemic zone both in hearts isolated from NTG-tolerant and non-tolerant rats. The magnitude of the effect was similar in the two groups. These results suggest that the anti-ischaemic effect of NTG involves direct myocardial mechanisms independent of its vascular action and that vascular tolerance to NTG does not affect this direct protective action.
Ferdinandy
P
P
Dept of Biochemistry, Szent-Györgyi University, Szeged, Hungary.
Szilvássy
Z
Z
Csont
T
T
Csonka
C
C
Nagy
E
E
Koltai
M
M
Dux
L
L
D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects; D004361:Drug Tolerance; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D066298:In Vitro Techniques; D008297:Male; D017202:Myocardial Ischemia / Q000517:prevention & control*; D005996:Nitroglycerin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; D005996:Nitroglycerin