Ultrasound-targeted microbubble destruction rapidly improves left ventricular function in rats with ischemic cardiac dysfunction

Background: Previous studies have demonstrated the efficacy of ultrasound-targeted microbubble destruction (UTMD) in the treatment of ischemic heart failure (HF). The purpose of this study was to explore the mechanism by which UTMD improves ischemic HF. Methods: An ischemic heart failure model was established using Sprague-Dawley rats. Rats were randomly divided into 7 groups: sham group, HF group, HF + MB group, HF + ultrasound (US) group, HF + UTMD group, HF + UTMD+LY294002 group, and HF + LY294002 group. Serum BNP level and echocardiographic parameters were measured to evaluate cardiac function. PI3K/Akt/eNOS signaling pathway protein levels were detected by immunohistochemistry (IHC) and western blotting. The concentrations of nitrous oxide (NO) and ATP were detected by ELISA, and hematoxylin and eosin (HE) staining was used to evaluate myocardial tissue. Results: UTMD rapidly improved ejection fraction (EF) (HF: 37.16 +/- 1.21% vs. HF + UTMD: 46.31 +/- 3.00%, P < 0.01) and fractional shortening (FS) (HF: 18.53 +/- 0.58% vs. HF + UTMD: 24.05 +/- 1.84%, P < 0.01) in rats with ischemic HF. UTMD activated the PI3K/AKT/eNOS signaling pathway (HF vs. HF + UTMD, P < 0.01) and promoted the release of NO and ATP (HF vs. HF + UTMD, both, P < 0.05). Inhibition of the PI3K/AKT/eNOS signaling pathway by LY294002 worsened EF (HF: 37.16 +/- 1.21% vs. HF + LY294002: 32.73 +/- 3.05%, P < 0.05), and the release of NO and ATP by UTMD (HF + UTMD vs. HF + UTMD+LY294002, P < 0.05). Conclusions: UTMD can rapidly improve cardiac function in ischemic HF by activating the PI3K/Akt/eNOS signaling pathway and promoting the release of NO and ATP.