ABSTRACT
<p><b>AIM</b>Probe into protective action of taurine against exercise-induced myocardial damage in rats after exhaustive exercise.</p><p><b>METHODS</b>Using the model of exhaustive exercise, the present study researches into effects of taurine on the content of triiodothyronine (T3) and tetraiodothyronine (T4) in serum and myocardium as well as the activity of T(4) 5' deiodinase (T(4)5'-DI) and second messenger cAMP in myocardium of rats.</p><p><b>RESULTS</b>The content of T3 in serum and myocardium, T(4)5'-DI activity, second messenger cAMP in myocardium increased significantly (P < 0.01) while that of T4 in serum and myocardium did not change significantly after exhaustive swimming. The supplement of taurine might significantly inhibit above changes caused by exhaustive exercise.</p><p><b>CONCLUSION</b>Taurine could protect myocardium from exhaustive exercise induced damage by inhibiting hypermetabolism of thyroid hormone and change of second messenger.</p>