Histamine aggravated levothyroxine-induced cardiomyopathy in guinea pigs
Abstract
AIM: To study effects of histamine on cardiomyopathy.
METHODS: Cardiomyopathy model was developed in guinea pig by i.p. levothyroxine
0.5 mg.kg-1.d-1 for 10 d. Langendroff's hearts were perfused. ECG and contractile
force were recorded. Histamine (5 micrograms) was given by intra-aortic
injection. Histamine content of coronary venous effluent was determined
fluorometrically.
RESULTS: Attack of histamine on cardiomyopathy was severer than that in normal
hearts. Tachycardia was more prominent; atrioventricular conduction block
occurred earlier; decrease in coronary flow was more marked. Uptakes of histamine
were 37% in the model and 19% in the normal hearts (P < 0.01).
CONCLUSION: Histamine aggravated levothyroxine-cardiomyopathy.
Keywords:
METHODS: Cardiomyopathy model was developed in guinea pig by i.p. levothyroxine
0.5 mg.kg-1.d-1 for 10 d. Langendroff's hearts were perfused. ECG and contractile
force were recorded. Histamine (5 micrograms) was given by intra-aortic
injection. Histamine content of coronary venous effluent was determined
fluorometrically.
RESULTS: Attack of histamine on cardiomyopathy was severer than that in normal
hearts. Tachycardia was more prominent; atrioventricular conduction block
occurred earlier; decrease in coronary flow was more marked. Uptakes of histamine
were 37% in the model and 19% in the normal hearts (P < 0.01).
CONCLUSION: Histamine aggravated levothyroxine-cardiomyopathy.