Chick Embryos as an Alternative Experimental Animal for Cardiovascular Investigations: Stable Recording of Electrocardiogram of Chick Embryosin Ovoon the 16th Day of Incubation

Self Cite

The drug-drug interactions between antiarrhythmic drugs were studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. Procainamide or flecainide with and without propranolol was injected into the air sac of a fertilized egg. Electrocardiograms (ECGs) were recorded 0 to 60 min after the injection. After each drug injection alone, the heart rate was not different compared with the control. However, the heart rate was significantly decreased by combinations of procainamide and propranolol or flecainide and propranolol. In addition, arrhythmia was produced in combination with propranolol. These findings indicate that the drug-drug interactions between antiarrhythmic drugs have a marked influence on the heart rate in chick embryos.

Section: Discussionmentioning

confidence: 99%

Section: 2)mentioning

confidence: 99%

Drug-Drug Interactions between Antiarrhythmic Drugs in Chick Embryos

Yoshiyama¹,

Sugiyama

Kanke³

et al. 2004

Self Cite

“…[1][2][3][4][5][6][7][8][9] Recently, we reported those thyroid abnormal models in chick embryos treated with thiamazol showed a similar reaction to digoxin, as in human. 10) From these experiments, we expected that it might be able to produce an experimental diabetes model by the developing inhibition of the endocrine hormone in the pancreas of chick embryos.…”

mentioning

confidence: 90%

Experimental Diabetes Model in Chick Embryos Treated with Streptozotocin

Yoshiyama¹,

Sugiyama²,

Kanke³

2005

Self Cite

The aim of the present study was to investigate whether diabetes model can be made by treatment of streptozotocin (STZ) in chick embryos and this model can be used to predict the effect of drug. When STZ (0.3 mg/egg) was injected into the albumen of fertile eggs on the 14th day of incubation, level of blood glucose significantly increased than that of the control on the 17th day of incubation, and level of serum insulin significantly decreased. In addition, the enhanced level of blood glucose in STZ-treated embryos reduced by injection of human insulin. In conclusion, STZ-treated embryos may be applicable to evaluate human insulin and anti-diabetes drugs as an experimental diabetes model.

“…In order to develop alternative methods, we have studied the biological effects of drugs on the cardiovascular system of chick embryos using physiological techniques. [7][8][9][10][11] We have evaluated the toxic interactions between propranolol and disopyramide in chick embryos. 12,13) The present study evaluated the effect of the hypothyroidism induced by thiamazole on the toxic interaction between propranolol and disopyramide in chick embryos.…”

mentioning

confidence: 99%

Influence of Hypothyroidism Induced by Thiamazole on the Toxic Interaction between Propranolol and Disopyramide in Chick Embryos

Yoshiyama¹,

Kanke²

2005

Antithyroid drugs, thiamazole and propylthiouracil, have been widely used as therapeutic drugs in patients with hyperthyroidism. Toxicological studies have shown that the use of antithyroid drugs at an overdose causes functional and morphological changes in the thyroids in rats and dogs. 1,2) In addition, it has been reported that functional abnormalities of the thyroid gland are often accompanied by heart disease and can show unexpected responses to cardiotonics, such as digoxin.3) Therefore, to predict the effects of cardiovascular drugs, experimental animals with a very sensitive heart condition such as hypothyroidism or hyperthyroidism are required to be used. A convenient thyrotoxic model would be of great benefit for evaluating the side effects and toxicity of cardiovascular drugs.An experimental animal model with heart disease originated from abnormalities of the thyroid gland in chick embryos has been produced by the treatment with thiamazole and the pharmacological and toxicological effects of cardiotonic were examined using this model. 4)Recently, many antiarrhythmic drugs have been put on the market in Japan and classified into subcategories. Such classification of antiarrhythmic mechanisms should prove of value in predicting the therapeutic as well as toxic effects of different agents, and may be particularly important in planning combination therapy for resistant arrhythmias. Drugdrug interactions have been demonstrated for a variety of drugs, including propranolol and disopyramide, in the treatment of heart failure patients. 5,6) With the recent concern for animal rights, experimental studies using mammals have been limited in number and methods. Thus, based on social acceptance, experimental studies using chick embryos have drawn attention. In order to develop alternative methods, we have studied the biological effects of drugs on the cardiovascular system of chick embryos using physiological techniques. [7][8][9][10][11] We have evaluated the toxic interactions between propranolol and disopyramide in chick embryos. 12,13) The present study evaluated the effect of the hypothyroidism induced by thiamazole on the toxic interaction between propranolol and disopyramide in chick embryos. MATERIALS AND METHODSFertilized eggs of White Leghorns (Omiya Poultry Laboratory, Saitama, Japan) were incubated at 37.5Ϯ0.2°C at a relative humidity of about 65%, turned automatically every hour.Thiamazole (Chugai Pharmaceutical, Tokyo, Japan), propranolol preparation (Sumitomo Pharmaceutical, Tokyo, Japan) and disopyramide preparation (Chugai Pharmaceutical, Tokyo, Japan) were used for the treatment. 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.Propranolol at 0.1 mg/egg and disopyramide at 0.3 mg/egg and were injected into the air sac of each fertilized egg on the 16th day of incubation.After the injection of propranolol and disopyramide into the thiamazole treated eggs ...