ABSTRACT
Objective:To investigate the mechanism of levosimendan on acute kidney injury after cardiopulmonary resuscitation (CPR) in rats.Methods:Twenty-five healthy adult male SD rats were randomly divided into three groups: control group ( n=5), levosimendan group ( n=10) and experimental group ( n=10). A cardiac arrest-cardiopulmonary resuscitation model was established using smothering method in the experimental group and levosimendan group. The levosimendan group was treated with levosimandan during and after resuscitation, while the experimental group was given equivalent volume of saline solution during and after resuscitation, and the control group was only given equivalent volume of saline without performance of CPR. The rats in the three groups were sacrificed at 6 h after resuscitation. The serum and kidney tissue samples were collected. Serum biochemical indicators [serum creatinine (Scr), blood urea nitrogen (Bun), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)] were measured. HE staining and Paller score were used to identify the degree of kidney damage. Apoptosis was estimated by TUNEL staining. Western blot was used to detect the expression levels of phosphorylation of extracellular regulated protein kinases (p-ERK). One-way analysis of variance was used to compare the mean values of normally distributed measurement data between groups. Comparisons between groups were performed using the least significant difference t-test. Results:Scr (85.02±1.31) μmol/L, Bun (7.36±0.13) mmol/L, Paller score (7.3±0.2), IL-1β (302.20±17.35) pg/mL, IL-6 (564.60±23.24) pg/mL and TNF-α (1346±83.73) pg/mL in the experimental group were significantly higher than those of the control group [(15.94±0.96) μmol/L, (2.95±0.18) mmol/L, (0.7±0.2), (7.27±0.44) pg/mL, (51.30±2.87) pg/mL, and (10.39±0.52) pg/mL] (all P<0.01). Compared with the experimental group, Scr (63.88±2.01) μmol/L, Bun (5.45±0.47) mmol/L, paller score (4.8±0.2), IL-1β (78.61±3.66) pg/mL, IL-6 (297.90±13.64) pg/mL and TNF-α (276.2±20.18) pg/mL were significantly decreased in the levosimendan group (all P<0.01). TUNEL staining showed that levosimendan could improve the apoptosis of renal cells ( P<0.01). The expression of p-ERK protein in the levosimendan group was significantly higher than that in the experimental group ( P<0.01). Conclusions:Lovosimendan could attenuate acute kidney injury following cardiac arrest and cardiopulmonary resuscitation via suppression apoptosis. The mechanism of levosimendan protective effect might be associated with activation of ERK signaling pathway.