Influence of hypothyroidism induced by thiamazole on the toxicity of amitriptyline in chick embryos

Abstract

The effect of hypothyroidism induced by thiamazole on the toxicity of amitriptyline was studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. 1.2 mg/0.2 ml/egg of thiamazole was injected into the albumen of fertilized eggs on the 9th day of incubation. The control group was given 0.2 ml/egg of physiological saline in the same manner. Amitriptyline at 1 mg/egg was injected into the air sac of fertilized eggs on the 16th day of incubation. Electrocardiograms were recorded 0 to 60 min after the injection. After the injection of amitriptyline into the thiamazole-treated eggs, the heart rate was significantly decreased compared with the untreated eggs. These findings indicate that hypothyroidism induced by thiamazole has a marked influence on the toxicity of amitriptyline in chick embryos. © 2006 Pharmaceutical Society of Japan.