Objectives: It was found that alpha-enolase was dramatically up-regulated in the hypertrophic hearts of SHR in our previous study. The purposes of this study were to examine the expression pattern of alpha-enolase in pre- and postnatal myocardium of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats, and to explore the relationship between the overexpression of alpha-enolase and left ventricular hypertrophy.
Methods: HE staining was used for the measurement of cardiac hypertrophy. Immunohistochemical technique was used to evaluate the location of alpha-enolase. The expressions of alpha-enolase in the left cardiac ventricles at different development times were examined by Real-time RT-PCR and Western blot.
Results: Cardiac hypertrophy was found in SHR rats at 4 weeks of age and remained up to 24 weeks of age. The signals of alpha-enolase protein were strong and existed extensively in hypertrophic myocardium in SHR, while in the normal myocardium of WKY, the signals were scarcely found and weak. The levels of alpha-enolase mRNA and protein in SHR and WKY hearts during fetal stage and newborn stage were similar, while from 4 weeks of age to 24 weeks of age, accompanied by the cardiac hypertrophy, the levels of alpha-enolase mRNA and protein in left ventricle of SHR were significantly higher than that in WKY.
Conclusions: The expressions of alpha-enolase in the left ventricle of the rats during normal and pathological cardiac development were different. This phenomenon provides the potential clues to understanding pathophysiological mechanisms in cardiac hypertrophy of SHR.