ABSTRACT
To study the effect of different exercise intensities on cardiac endocrine function, with radioimmunoassay, immunohistochemistry and the technique of computer image analysis, the level of plasma ANP and the expression of ANP in myocardial cells of rats with different training intensities were investigated. The result showed that with the increasing of exercise intensity,the level of ANP in plasma increased progressively, the expression of ANP in myocardial cells increased remarkably after moderate and heavy exercise training while it decreased remarkably after exhaustive exercise training. Results suggested that different exercise intensities revealed different effects on adaptation of cardiac endocrine function.
ABSTRACT
To study the effect of exercise on gene expression of natriuretic peptide receptors (NPRs) in the heart, using immunofluorescent method, in situ hybridization, laser confocal scanning microscopy and the technique of computer image analysis, the distribution of NPRs in the heart and the alterations of gene expression of NPRs on the animal model of different training intensity were investigated. The result showed that NPRs located mainly in the endocardium, the sarcolemma of myocardial fiber, the connective tissue around myocardial fiber and the wall of coronary artery branch. After moderate and heavy exercise training, the gene expression of natriuretic peptide receptor-A (NPR-A) upregulated and natriuretic peptide clearance receptor (NPR-C) downregulated, whereas the gene expression of NPR-A downregulated and NPR-C upregulated after exhaustive exercise.