Author + information
- Lai Xin and
- Xi Wang
To discuss the effect of Neuregulin-1 on cardiac autonomic nervous remodeling post-myocardial infarction on rats and supply the evidences for clinical use.
45 SD rats were randomized averagely to three groups: SO, MI and MI+N group. A rat MI model was established by left anterior descending coronary artery ligation. Then, the rats of MI+N group were given neuregulin-1 respectively. After 4 weeks, the rats were given echocardiography test, including left ventricular end-systolic inner diameter (ESD), left ventricular diastolic diameter (EDD), left ventricular end-systolic volume (ESV), left ventricular end-diastolic volume (EDV), left ventricular ejection fraction (EF%), and left ventricular fractional shortening (FS%). Tyrosine hydroxylase (TH), growth associated protein 43 (GAP43), choline acetyltransferase (CHAT) and vesicular acetylcholine transporters (VACHT) mRNA and protein expression were detected in the ischemic zone surrounding by RT-PCR, western blotting, respectively.
1. Compared to SO group, ESD, EDD, ESV, EDV significantly elevated in MI group (0.56±0.04 vs 0.35±0.015, 0.77±0.023 vs 0.62±0.021, 0.41±0.08 vs 0.11±0.015, 0.92±0.12 vs 0.55±0.047, P<0.05), while the value of EF, FS significantly decreased (53.28±0.48 vs 80.46±4.35, 23.88±0.21 vs 43.97±4.52, P<0.05); Compared with MI group, EF, FS value significantly increase in MI+N group (73.85±4.19 vs 53.28±0.48, 38.02±3.72 vs 23.88±0.21, P<0.05), and ESD, EDD, ESV, EDV significantly decreased in MI+N group (0.42±0.017 vs 0.56±0.04, 0.67±0.035 vs 0.77±0.023, 0.18±0.021 vs 0.41±0.08, 0.70±0.02 vs 0.92±0.12, P<0.05).
2. In the level of mRNA, compared to SO group, TH, GAP43, CHAT, VACHT value obviously increased in MI group (4.78±0.505 vs 11.04±0.252, 4.94±0.452 vs 1.21±0.453, 3.60±0.797 vs 0.91±0.121, 4.13±0.890 vs 1.00±0.205, P<0.01); Compared with MI group, TH, GAP43, CHAT value obviously decreased in MI+N group (3.59±0.280 vs 4.78±0.505, 3.95±0.165 vs 4.94±0.452, 2.14±0.466 vs 3.60±0.797, P<0.05); However, VACHT have no difference in statistical (4.22±0.382 vs 4.85±0.450, 2.97±0.424 vs 4.13±0.890, P>0.05).
3. In the level of protein, compared to SO group, the TH, GAP43, CHAT, VACHT in MI group markedly elevated (0.678±0.102 vs 0.185±0.076, 0.837±0.043 vs 0.124±0.062, 1.129±0.450 vs 0.409±0.149, 0.749±0.176 vs 0.231±0.096, P<0.05); Compared with MI group, TH, GAP43 markedly dropped in MI+N group (0.364±0.141 vs 0.678±0.102, 0.445±0.043 vs 0.837±0.043, P<0.05); CHAT, VACHT decreased in MI+N group, but no difference compared to MI group (0.812±0.231 vs 1.129±0.450, 0.693±0.141 vs 0.749±0.176, P>0.05).
The data indicated that Neuregulin-1 improved the cardiac function post-myocardial infarction. Neuregulin-1 can obviously inhibit the sympathetic nerve and can not apparently effect on the vagus nerve to modulate auto nervous system remodeling post.