姜黄素对干热环境热射病大鼠肾损伤及细胞凋亡的影响

Effects of curcumin on renal injury and apoptosis in heat stroke rats under dry heat environment

目的探讨姜黄素对干热环境热射病大鼠肾脏损伤的病理变化及细胞凋亡的影响。方法SPF级成年健康雄性SD大鼠50只,在SPF级环境适应性饲养1周,按随机数字表法分为5组:常温对照组、干热对照组、姜黄素低浓度处理组(50 mg/kg)、姜黄素中浓度处理组(100 mg/kg)、姜黄素高浓度处理组(200 mg/kg),每组10只。常温及干热对照组给予0.9%生理盐水灌胃,姜黄素组大鼠给予不同浓度姜黄素溶液灌胃,连续7 d。第8天除常温对照组外,其余4组大鼠均转移到模拟干热环境实验舱中。入舱实验的第150 min达到热射病状态,麻醉处死大鼠后留取尿液、肾组织进行分析,肾损伤分子-1(KIM-1)试剂盒检测尿液KIM-1水平变化,苏木精-伊红(HE)染色观察各组大鼠肾组织病理形态变化,进行肾损伤病理学评分,细胞凋亡缺口末端标记技术(TUNEL)检测细胞凋亡并计算凋亡率。结果常温对照组尿液KIM-1水平、肾损伤病理学评分、肾组织细胞凋亡率分别为[(100.36±5.54)ng/L]、[(35.50±9.52)分]、[(0.55±0.04)%];干热对照组大鼠各指标分别为[(1060.57±75.50)ng/L]、[(710.67±74.60)分]、[(5.53±0.48)%];姜黄素低浓度处理组各指标分别为[(945.73±48.07)ng/L]、[(701.67±64.84)分]、[(5.10±0.37)%];姜黄素中浓度处理组各指标分别为[(639.17±44.71)ng/L]、[(365.00±34.06)分]、[(2.05±0.35)%];姜黄素高浓度处理组各指标分别为[(592.67±34.29)ng/L]、[(289.00±35.08)分]、[(1.33±0.20)%]。各项指标水平在各组间比较,均差异有统计学意义(F=373.70,203.16,289.81;均P<0.01),干热对照组KIM-1水平和肾损伤病理学评分均明显高于常温对照组(t=31.04,21.99;均P<0.01)。肾损伤病理学评分和肾组织细胞凋亡率在姜黄素低浓度组和干热对照组之间比较,均差异无统计学意义(t=0.22,1.74;均P>0.05),姜黄素中浓度处理组(t=10.33,14.43)、高浓度处理组(t=12.53,19.82)与干热对照组之间比较,均差异有统计学意义(均P<0.01)。结论姜黄素预处理对干热环境热射病大鼠肾损伤具有一定的保护作用,可能通过阻断肾细胞凋亡通路发挥对肾脏损伤的保护作用。

Objective To investigate the effect of curcumin pretreatment on renal injury and apoptosis in heat stroke rats in dry heat environment.MethodsFifty adult SD male rats were randomly divided into 5 groups according to the random number table,including normal temperature control group,dry heat control group,low concentration curcumin pretreatment group(curcumin 50 mg/kg),moderate concentration curcumin pretreatment group(curcumin 100 mg/kg),and high concentration curcumin pretreatment group(curcumin 200 mg/kg),10 rats in each group.The two control groups were given a gavage of normal saline,while curcumin pretreatment group were given a gavage of curcumin with the corresponding concentration once a day for 7 consecutive days.At the 8th day,except for normal temperature control group,other group were transferred to the simulated climate cabin of dry heat environment of desert.At the time of 150th minute since the experiment began,the rats were in heat stroke states,the urine and renal tissue were harvested from the anesthetized rats.The KIM-1 level was detected by KIM-1 kit in urine.Pathological changes of renal tissues were observed by HE staining,and pathological injury score were evaluated.The apoptosis of renal cells was detected by TUNEL staining method.ResultsIn normal temperature control group,the levels of KIM-1,renal injury pathological score,apoptosis rate of renal cell were[(100.36±5.54)ng/L],[(35.50±9.52)points],[(0.55±0.04)%],respectively.They were[(1060.57±75.50)ng/L],[(710.67±74.60)points],[(5.53±0.48)%]in dry heat control group.The indexes levels of the low,medium,high concentration curcumin pretreatment group were[(945.73±48.07)ng/L,(701.67±64.84)points,(5.10±0.37)%],[(639.17±44.71)ng/L,(365.00±34.06)points,(2.05±0.35)%],[(592.67±34.29)ng/L,(289.00±35.08)points,(1.33±0.20)%],respectively.All the three indexes levels were significantly different among the 5 groups(F=373.70,203.16,289.81,all P<0.01).The KIM-1 level and renal injury pathological score of dry heat control group were significantly higher than those of normal temperature control group(t=31.04,21.99,all P<0.01).The renal injury pathological scores and apoptosis rate of renal cell had no significant difference in the dry heat control group and the low concentration curcumin pretreatment group(t=0.22,1.74,all P>0.05),and there were statistically significant differences between medium(t=10.33,14.43),high(t=12.53,19.82)concentration groups and dry heat control group(all P<0.01).ConclusionCurcumin pretreatment has protective effect on the renal injury of heat stroke rats in dry heat environment,the protective effects may partly through inhibiting apoptosis of the renal cell in such situation.