MYOCARDIAL AND GASTROINTESTINAL RELEASE OF VASOACTIVE-INTESTINAL-PEPTIDE DURING EXPERIMENTAL ACUTE MYOCARDIAL-INFARCTION

Background Vasoactive intestinal peptide (VIP) acts as a vasodilator o n coronary and gastrointestinal arteries, During coronary occlusion, t he locally released VIP may exert a protective effect on the heart, bu t it may aggravate the shock state through its vasodilatory effect in the gastrointestinal tract. Methods After left thoracotomy, the left c ircumflex coronary artery (LCx) was prepared, and a pneumatic occluder was introduced around it, After 60 min of coronary occlusion, the LCx was reperfused in six dogs (reperfusion group), while in another six the occlusion was maintained for 6 h (occlusion group), Five dogs serv ed as sham-operated controls. The plasma concentration of VIP was dete rmined at baseline, after the 60 min occlusion and 10 min, 3 h and 6 h after reperfusion, or 3 h and 6 h after continuous occlusion in the c oronary sinus and in the femoral and portal veins. Results The plasma VIP concentrations in all three vessels were increased after 60 min of LCx occlusion, During the 6 h constant coronary occlusion, concentrat ions remained increased in both the coronary sinus and the portal vein , but not in the femoral vein. In the reperfusion group, 10 min after reperfusion, the plasma concentrations of VIP in all three vessels had decreased. Conclusions Coronary artery occlusion causes a longterm in crease in plasma VIP concentrations that decreases after reperfusion, when measured in the portal vein and coronary sinus, but not in the fe moral veins. (C) Rapid Science Publishers.