Beneficial effect of HEPES buffer in repeated coronary reperfusion.
BACKGROUND
We have demonstrated previously that, when repeated reperfusion is performed after reocclusion, there is a decrease in the amount of myocardial salvage, despite early reperfusion. Treatment with nisoldipine induced a beneficial effect by reduction of infarct size in this experimental model.


OBJECTIVE
To study the effect of HEPES buffer on infarct size, using a repeated-reperfusion model.


METHODS
The left anterior descending coronary artery was occluded in anesthetized dogs. Thirty minutes after the occlusion, dogs were allocated randomly to either the treatment group (n = 7; HEPES 0.64 mmol/l infused intravenously throughout the experiment) or the control group (n = 8; saline). Occlusion was maintained for 2 h, followed by 1 h of reperfusion, then 1 h of reocclusion and 2 h of second reperfusion. An in-vivo area at risk was determined by gentian violet staining, and infarct size was defined and quantitated by triphenyl-tetrazolium chloride staining.


RESULTS
Hemodynamic measurements were similar in both groups. Mass of necrosis/mass at risk was significantly smaller in the HEPES group (30.7 +/- 1.6%, mean +/- SEM) compared with controls (50.6 +/- 3.8%, P < 0.001).


CONCLUSIONS
Treatment with HEPES induces a beneficial effect by reduction of infarct size in repeated coronary reperfusion.
Hammerman
H
H
Department of Cardiology, Rambam Medical Center, Haifa, Israel. h-hammerman@rambam.health.gov.il
Ramadan
R
R
Hir
J
J
Moscovitz
M
M
D000704:Analysis of Variance; D000818:Animals; D002021:Buffers; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D004195:Disease Models, Animal; D004285:Dogs; D006531:HEPES / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects; D007262:Infusions, Intravenous; D009203:Myocardial Infarction / Q000473:pathology / Q000517:prevention & control; D015425:Myocardial Reperfusion / Q000379:methods*; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D011897:Random Allocation; D012016:Reference Values; D015996:Survival Rate
D002021:Buffers; D006531:HEPES