Objective: To investigate the relationship between endothelin-1 (ET-1) and tumor necrosis factor-alpha and myocardial microcircular dysfunction during coronary microembolization (CME).
Methods: CME was induced in 10 miniswine by selective infusion of microspheres (45 microm) into left anterior descending artery (LAD). We measured (1) coronary sinus level of ET-1, TNF-alpha using radioimmunoassay; (2) CFR, a measure of microvascular integrity, using Doppler flow wire in LAD at baseline and different doses of microspheres.
Results: CFR decrease significantly with different doses of microspheres (vs. baseline, P < 0.05). Level of ET-1, TNF-alpha increased significantly with doses of 5 x 10(4) and peaked with 10 x 10(4). Interestingly, ET-1 progressively decrease while TNF-alpha persistently elevated from doses of 12 x 10(4) to 15 x 10(4). There are reverse correlations between ET-1 and CFR (r = -0.31, P < 0.05).
Conclusions: The extent of microvascular injury wasn't linearly related to the extent of ME, where, it closely associated with myocardial ET-1.