Authors: Ana C Omoto, Jussara M Docarmo, Bejamin Nelson, Nikaela Aitken, Xuemei Dai, Sydney Moak, Zhen Wang, Alan J Mouton, Xuan Li, John E Hall, Alexandre A Da Silva
Published: 2023-06-15
DOI: 10.1161/circ.146.suppl_1.10134
Source: Full article
We previously demonstrated that central nervous system (CNS) administration of leptin improves left ventricular (LV) function after myocardial infarction through mechanisms that are poorly understood. Increased cardiac sympathetic activity is an important compensatory mechanism to maintain cardiac output after ischemic injury, and previous studies showed that centrally-administered leptin increases sympathetic outflow to various tissues. In the present study, we tested the hypothesis that leptin’s CNS-mediated cardioprotective effects are mediated via cardiac sympathetic nerves. Male and female Wistar rats (~8 weeks of age) were submitted to cervical ganglia denervation (CGx) and instrumented with an intracerebroventricular (ICV) cannula in the brain lateral ventricle. After recovery and baseline assessment of cardiac function by echocardiography (ECHO) and an exercise performance test (Vmax), myocardial ischemia/reperfusion (I/R) was induced by temporary (60 min) ligation of the left anterior descending coronary artery. Vehicle (saline, 0.5 μL/hr) or leptin (0.62 μg/hr) was infused chronically for 28 days starting 20 min after reperfusion using osmotic pumps implanted subcutaneously in the scapular region and connected to the ICV cannula. Cardiac function was assessed weekly by ECHO. At the end of week 4, a final Vmax was performed and +dP/dt