Evaluation of endothelial and inducible nitric oxide synthase genes expression in the heart of broiler chickens with experimental pulmonary hypertension

Abstract

1. To clarify the effect of T₃-induced pulmonary hypertension on endothelial and inducible nitric oxide synthase (eNOS and iNOS) mRNA expression in the ventricles of the heart, semi quantitative reverse transcription-PCR was performed on total RNAs isolated from broiler chicken hearts after feeding supplementary T₃ (1⋅5 mg T3/kg) for 6 weeks. NO metabolites (nitrite/nitrate) of serum were measured.

2. The eNOS and iNOS genes were expressed in the right and left ventricles of control and T₃-treated broilers at 12, 28 and 49 d of age. The relative amount of eNOS mRNA expression in the right and left ventricles did not significantly differ between control and T₃-treated broilers at any age.

3. The relative amount of iNOS mRNA expression in the right and left ventricles was lower in T₃-treated broilers than in control broilers at 49 d of age, but not at 12 or 28 d.

4. The amount of NO metabolites was reduced in the serum of T₃-treated chickens at 49 d of age when compared with the control.

5. It is concluded that eNOS and iNOS genes are normally expressed in the heart of broilers. It is probable that impaired NO synthesis and reduction of iNOS gene expression in the heart ventricles are involved in the pathophysiology of cardiac function in broilers with pulmonary hypertension.

Acknowledgements

This work had been supported by funds granted by the Applied Research Centre, Vice Chancellor for Research of University of Tehran. The authors would like to thank Dr Zamani Moghadam for his assistance for rearing the chicks during this research and also thank Ms Farzaneh Touyeh for editing this text.