LOCAL CHANGES IN THE PLASMA ENDOTHELIN LEVEL IN THE CORONARY-ARTERY IMMEDIATELY AFTER PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

Endothelin plays an important role in cardiovascular pathology. As one of the most important endothelium-derived vasoconstrictor substances, endothelin together with endothelium-derived vasodilating factor cont rol vascular tone and contribute to the vasoconstrictory response if t he production of endothelium-derived vasodilating factor is impaired. The aim of the study was to assess the changes of the local endothelin level in coronary circulation immediately after percutaneous translum inal coronary angioplasty (PTCA). Plasma endothelin levels were measur ed in blood samples from the peripheral vein and ostium of the coronar y artery before the angioplasty, and from the distal coronary artery j ust beyond the dilated segment and the peripheral vein immediately aft er the procedure. The plasma endothelin level was significantly higher in the ostium of the coronary artery already prior to PTCA as compare d to the peripheral vein (10.9+/-3.4 vs. 7.2+/-2.1 pg/ml, p <0.005). T here was no change in the endothelin level in the coronary artery dist al to the dilated segment immediately after the procedure as compared to the initial level, although this level was higher than the postangi oplasty venous level (9.8+/-2.9 vs. 7.7+/-2.0 pg/ml, p <0.005). Indivi dual changes in coronary-artery plasma endothelin levels as a response to coronary angioplasty were disparate. An increase and a decrease in coronary artery plasma endothelin levels by more than 2 pg/ml after c oronary angioplasty were observed in 3 and 6 subjects, respectively. I n conclusion, increased plasma endothelin levels were found in blood s amples drawn from the coronary artery as compared to the peripheral ve in. There was no further change in the plasma endothelin level in the coronary artery distal to the dilated segment after angioplasty; howev er, the individual responses were disparate.