The 8-10 weeks old specific pathogen free (SPF) male Sprague-Dawley (SD) rats were divided into
sham operation group (
Sham group), positive drug control group and
Xuebijing group by the random number table method, with 10 rats in each group. The cecal
ligation and
puncture (CLP) with large
ligation (ligated 75% of the cecum) was used to prepare a rat high-grade
sepsis model; in the
Sham group, the cecum was stretched without
ligation or
puncture. Due to the high mortality of CLP with large
ligation,
Xuebijing injection (4 mL/kg, 12 hours per time) and
imipenem/cilastatin injection (90 mg/kg, 6 hours per time) were administered to the rats in the
Xuebijing group via the tail vein immediately after the model was produced.
Normal saline and
imipenem/cilastatin were administered to the rats by the same methods in the positive drug control group. The rats in the
Sham group were treated with the same volume of
normal saline as any of the other two groups at the same frequency. At 48 hours after model reproduction, the mean arterial pressure (MAP) and blood
lactic acid (Lac) of the rats were measured. The renal cortical microcirculation was monitored by using side stream dark-field imaging. Renal
hypoxia signals were assessed by
pimonidazole chloride immunohistochemistry. Plasma EMP levels were determined by using flow cytometry, and then the correlation between EMP and microcirculation parameters of renal cortex was analyzed. At the same time, the serum
creatinine (SCr) was measured, and the renal injury score (Paller score) was used to evaluate the severity of renal tissue pathological damage.
RESULTS: Compared with the
Sham group, perfused vessel density (PVD), microvascular flow index (MFI) and MAP in the positive drug control group and the
Xuebijing group decreased significantly, the positive expression of
hypoxia probe (
pimonidazole) increased, Lac, EMP, Paller score and SCr increased significantly. However, compared with the positive drug control group, the renal cortical microcirculation in the
Xuebijing group was improved significantly, PVD and MFI were increased significantly [PVD (mm/mm2): 16.20±1.20 vs. 9.77±1.12, MFI: 2.46±0.05 vs. 1.85±0.15, both P < 0.05], Lac was reduced significantly (mmol/L: 4.81±1.23 vs. 6.08±1.09, P < 0.05), MAP increased slightly [mmHg (1 mmHg = 0.133 kPa): 84.00±2.00 vs. 80.00±2.00, P > 0.05], suggested that
Xuebijing injection improved renal microcirculation perfusion in septic rats, and this effect did not depend on the change of MAP. The positive expression of pemonidazole in renal cortex of the
Xuebijing group was significantly lower than that of the positive drug control group [(35.89±1.13)% vs. (44.93±1.37) %, P < 0.05], suggested that
Xuebijing injection alleviated renal
hypoxia. The plasma EMP levels of rats in the
Xuebijing group were significantly lower than those in the positive drug control group (×106/L: 3.49±0.17 vs. 5.78±0.22, P < 0.05), and the EMP levels were significantly negatively correlated with PVD and MFI (r values were -0.94 and -0.95, respectively, both P < 0.05), indicated that the increase of plasma EMP was highly correlated with renal microcirculation disorder, and
Xuebijing injection inhibited the increase of plasma EMP levels. The Paller score in the
Xuebijing group was significantly lower than that in the positive drug control group (46.90±3.84 vs. 62.70±3.05, P < 0.05), and the level of SCr was also significantly lower than that in the positive drug control group (μmol/L: 121.1±12.4 vs. 192.7±23.9, P < 0.05), which suggested that
Xuebijing injection relieved kidney injury and improved renal function in septic rats.
CONCLUSIONS: