Protective effect of serotonin (5-HT2) receptor antagonists in ischemic rat hearts.

Serotonin (5-HT) may play a role in exacerbating thrombosis and coronary spasm during myocardial ischemia, but its role in mediating myocardial damage directly is not clear. We determined the effect of the 5-HT 2 receptor antagonists cinanserin (0.1-10 μM), ketanserin (0.3-10 μM), and LY 53857 (1-10 μM) on time to contracture, recovery of contractile function, and lactate dehydrogenase (LDH) release after 25-min global ischemia and 30-min reperfusion in isolated rat heart. All 5-HT 2 antagonists significantly increased time to contracture in a concentration-dependent manner (EC 25 =1.6, 5.5, and 6. 1 μM for cinanserin, ketanserin, and LY 53857, respectively)