【摘要】 目的观察C型钠尿肽(CNP)对肾缺血再灌注损伤大鼠肾功能、肾组织细胞凋亡的影响,并探讨其机制。方法将24只雄性Wistrar大鼠随机分为Sham组、IR组和CNP组,每组8只。各组大鼠均摘除左侧肾脏,IR组和CNP组用无创性小血管夹夹闭右肾动静脉,45 min后取下血管夹恢复肾脏血供,并分别于夹闭右肾动静脉的同时即刻持续缓慢输注生理盐水约2 mL、CNP 0.2μmol/(kg·min)至再灌注2 h;Sham组不夹闭右肾动静脉。再灌注24 h后取血测定血清肌酐(Cr)、尿素氮(BUN),取右肾以ELISA法测定肾组织环磷酸鸟苷(cGMP),TUNEL染色检测肾脏织的凋亡细胞,Western blot法检测肾脏组织蛋白激酶B(Akt)和β糖原合成酶激酶3β(GSK-3β)蛋白及其磷酸化蛋白。结果与Sham组比较,IR组大鼠血清Cr和BUN水平均升高(P均<0.01),肾组织cGMP浓度降低、细胞凋亡率升高(P均<0.05),肾组织中Akt、GSK-3蛋白磷酸化水平均降低(P均<0.01);与IR组比较,CNP组大鼠血清Cr和BUN水平均降低(P均<0.05),肾组织cGMP浓度升高、细胞凋亡率降低(P均<0.05),肾组织中Akt、GSK-3蛋白磷酸化水平均升高(P均<0.01)。结论 CNP减轻肾脏缺血再灌注大鼠肾功能损伤及肾脏组织细胞凋亡,其机制可能与提高肾组织cGMP水平,进而提高Akt和GSK-3β蛋白磷酸化有关。更多还原

【Abstract】 Objective To observe the effects of C-type natriuretic peptide( CNP) on renal function and renal tissue apoptosis in rats with renal ischemia-reperfusion( IR) injury and its mechanisms involved. Methods Twenty-four male Wistrar rats were randomly divided into the Sham group,IR group and CNP group( n = 8). All the rats were left unilaterally nephrectomized. In the IR group and CNP group,we nipped the right renal artery and vein with noninvasive small vascular clip for 45 min. CNP [0. 2 μg/( kg·min) ] and 2 mL physiological saline was infused immediately and slowly at the start of a 45-min renal ischemia for 2 h in the two groups,respectively. The right renal artery and vein in the Sham group was not treated by the clip. Rats were killed to obtain the blood at 24 h after I/R. The serum creatinine( Cr) and urea nitrogen( BUN) was measured,cyclic guanosine monophosphate( cGMP) in right renal tissues was measured by ELISA,and the apoptotic cells in kidney tissues was detected by TUNEL staining. The renal tissue protein kinase B( Akt),β glycogen synthase kinase 3β( GSK-3β) protein and their phosphorylated protein was measured by Western blotting. Results Compared with the Sham group,the levels of serum Cr and BUN were significantly increased( both P < 0. 01),the concentration of cGMP in renal tissues was decreased,and the apoptosis rate was increased( both P < 0. 05),the protein phosphorylation levels of Akt and GSK-3β in the renal tissues were decreased in the IR group( both P < 0. 05). Compared with the IR group,the levels of serum Cr and BUN were decreased( both P < 0. 05),the concentration of cGMP was increased in the renal tissues and the apoptosis rate was decreased( both P < 0. 05),the protein phosphorylation levels of Akt and GSK-3β in renal tissues were increased in the CNP group( both P < 0. 01). Conclusions CNP can alleviate IR-induced kidney injury and renal tissue apoptosis. The mechanism may be related to the increased renal tissue cGMP levels which effectively increase Akt and GSK-3β protein phosphorylation.更多还原