Excitotoxin-induced myocardial necrosis.

The excitotoxins, kainic acid and N-methyl-D-aspartic acid (NMDA), were injected bilaterally into the paraventricular hypothalamus of rats. Kainic acid elicited pressor responses, tachycardia and sudden cardiac death in Nembutal-anesthetized rats. Injections of NMDA caused cardiovascular stimulation on cessation of halothane anesthesia. Intramyocardial hemorrhage, hyaline myocardial necrosis and predominantly mononuclear inflammation were evident 48 h following NMDA. Labetalol pretreatment did not protect from nor did i.v. NMDA cause these changes. Intrahypothalamic excitotoxin injections cause deleterious myocardial changes.