Gram-Negative Sepsis Cardiomyopathy Model

In this study, gram-negative sepsis-induced cardiomyopathy model was established with lipopolysaccharide (LPS) (Sigma; L2280) or cecal ligation and puncture (CLP) [52 (link), 53 (link)]. For LPS-induced cardiomyopathy, mice weighed 22.3 ± 2.5 g were randomly underwent an intraperitoneal injection of LPS (10 mg/kg) or saline equally. The general appearance and heart function of the animals were monitored. After LPS stimulation for 24 h, the mice were sacrificed for subsequent experiments. The CLP surgery procedure was similar to previous studies with minor modifications [52 (link)]. Briefly, mice were anesthetized with 2% isoflurane (RWD, R510-22-4) with a maintained 37 °C body temperature. After exposure through a small anterior abdominal incision, the cecum was ligated with a 4–0 silk suture and was punctured twice with an 18-gauge needle. The cecum was then gently squeezed to extrude a small amount of stool from the puncture site to ensure complete perforation. Next, the cecum was relocated into the peritoneal cavity, and the abdominal incision was closed with 6–0 silk sutures. Sham-operated mice underwent the same operation procedure but without CLP. Subsequent experiments were performed 24 h after the operation.