Abstract:

Objective  To investigate the relationship between the dynamic expression of neurturin (NRTN) after myocardial infarction (MI) and vagal neural remodeling. Methods  54 male SPF Wistar rats were randomly assigned to six groups: 3 days after MI(n=10), 1 week after MI(n=10), 4 weeks after MI(n=10) and three corresponding sham-operated groups(n=8). The left anterior descending coronary artery was ligated to create rat MI models. Heart tissue was sampled from the infarct border and noninfarct left ventricular free wall (LVFW). RT-PCR and western blot were used to examine NRTN mRNA and protein expressions. RTPCR and immunohistochemistry were used to measure the expression and innervation of vagal nerve fibers. Results  The expressions of NRTN mRNA and protein significantly increased in the infarct border in the 1 week after MI group, which were higher than those in the 3 days and 4 weeks after MI groups(P<0.01). Moreover, compared with the corresponding sham-operated groups, the ChAT expression decreased in the 3 days after MI group while it significantly increased in the 1 and 4 weeks after MI groups. Conclusion  The dynamic expression of NRTN after MI is closely related to the cardiac vagal neural remodeling. Regulating NRTN expression may be a potential therapeutic target for improving the cardiac autonomic nervous imbalance and the prognosis of MI.

Key words: Myocardial infarction; Neurturin; Vagal nerves; Arrhythmia