For the experiments, male C57BL/6 mice were arbitrarily allocated into four groups: (1) sham, (2) SSI, (3) sham+verapamil (SH+VP), and (4) SSI+verapamil (SSI+VP). The verapamil hydrochloride (5 mg/kg body weight, Sigma-Aldrich Co., St. Louis, USA) was diluted in sterile 0.9% NaCl saline (100 μL total volume/animal) and injected intraperitoneally (i.p.) two hours after CLP surgery (SSI+VP) or the sham operation (SH+VP). Untreated control (sham) and untreated septic mice (SSI) received an equivalent volume of saline. The survival rates were monitored every 12 hours for five days after surgery using 10 animals per group (sham, SSI, SH+VP, and SSI+VP, n = 10 per group).