外源性肾上腺髓质素对肾脏创伤大鼠Th1/Th2的调节作用

Regulatory effects of exogenous adrenomedullin on Th1/Th2 following kidney trauma in rats

目的:观察外源性肾上腺髓质素(adrenomedullin,ADM)对大鼠肾脏创伤后外周血Th1/Th2的调节作用,并了解给药时间对此作用的影响。方法:实验于2005年在兰州大学实验中心进行。将104只Wistar大鼠随机分为4大组:①正常对照组(8只);不打击。②创伤组(32只);自由落体生物撞击仪撞击大鼠脊肋区,间接打击双侧肾脏造成肾脏Ⅰ级损伤。③创伤前注射ADM组(32只);打击同创伤组,打击前10min腹腔注射肾上腺髓质素0.1nmol/kg(终体积0.5mL)。④创伤后注射ADM组(32只):打击同创伤组,打击后10min腹腔注射肾上腺髓质素0.1nmol/kg(终体积0.5mL)。后3组分别在打击后1,6,12,24h各处死8只。采用酶联免疫斑点法测定Th1与Th2阳性率。结果:82只大鼠进入结果分析。①创伤组:Th1细胞在创伤后6h显著增加并达峰值,高于创伤后1h及正常对照组[(0.32±0.07)%,(0.13±0.06)%,(0.16±0.07)%,P<0.05,0.01];Th2各时间点比较均无差异;Th1/Th2在创伤后6h达高峰,创伤后24h降至正常对照组水平。②创伤前注射ADM组:Th1在创伤后6h低应答,在创伤后12h增高并达峰值,高于创伤后6h及正常对照组[(0.32±0.08)%,(0.08±0.06)%,(0.16±0.07)%,P<0.05,0.01];Th2在创伤后6-12h的变化趋势与Th1相同;Th1/Th2创伤后6h达最低,低于该时点创伤组(4.58±3.81,23.44±6.19,P<0.01),随后上升,至创伤后24h达高峰。③创伤后注射ADM组:Th1自创伤后1h逐渐上升,至24h达高峰,高于创伤后1,6h[(0.32±0.10)%,(0.10±0.04)%,(0.17±0.07)%,P<0.05,0.01],Th2细胞各时间点比较均无差异;Th1/Th2于创伤后1,6h接近正常对照组,然后逐渐上升,至创伤后24h达最高,高于正常对照组及该时点创伤组(22.49±12.64,5.33±4.55,4.78±3.15,P<0.01)。结论:①急性创伤早期(以创伤后6h为著),外源性肾上腺髓质素通过抑制Th1优势应答,具有校正Th1/Th2比例失衡的免疫调节作用。②急性创伤后最初6h内,创伤后给予肾上腺髓质素调节Th1/Th2平衡作用明显优于创伤前给药。

AIM： To observe the regulatory effects of exogenous adrenomedullin （ADM） on Th1/Th2 in peripheral blood of rats after renal trauma, and explore the influence of the administration time on the regulation. METHODS： The experiment was completed in experimental center of Lanzhou University in 2005. 104 Wistar rats were randomly divided into 4 groups： （1）control group （n =8） without trauma; （2）trauma group （n =32）： The double vertebral-costal region of rats were stroke by free fall bio-impactor to establish the models of Ⅰ grade kidney injury;（3）ADM injection before trauma group （n =32）： 0.1 nmol/kg ADM （terminal volume 0.5 mL） was administrated by intraperitoneal injection 10 minutes before the previous striking was done; （4）ADM injection after trauma group （n =32）： The previous striking was performed, and 10 minutes later, 0.1 nmol/kg ADM was administrated by intraperitoneal injection. Eight rats in the last three groups were executed at 1, 6, 12 and 24 hours after striking, respectively. Th1 and Th2 cells positive rates were detected by enzyme-linked immunospot assay. RESULTS： Eighty-two rats were involved in the result analysis. （1）Trauma group： The expression of Th1 was increased significantly and reached to its peak at 6 hour after trauma, which was higher than that at 1 hour after trauma and the control group [（0.32±0.07）%, （0.13±0.06）%, （0.16±0.07）%, P 〈 0.05, 0.01]; Th2 expression showed no significant difference between any two groups at each time point; Th1/Th2 reached the peak value at 6 hour after trauma and decreased to the normal level as the control group after 24 hours. （2）ADM injection before trauma group： The expressive bottom of Th1 appeared at 6 hour after trauma, increased until to peak at 12 hour after trauma, which was higher than that at 6 hour after trauma and the control group [（0.32±0.08）%, （0.08±0.06）%, （0.16±0.07）%, P 〈 0.05, 0.01]; the trend of Th2 during 6-12 hours after trauma was the same as that of Th1; Th1/Th2 reached the lowest value after 6 hours, which was lower than the trauma group at the same time point （4.58±3.81, 23.44±6.19, P 〈 0.01）, and increased gradually until to the peak at 24 hour. （3）ADM injection after trauma group： The expression of Th1 was increased gradually after 1 hour trauma until to its peak at 24 hour after trauma, which was higher than that at 1 and 6 hour after trauma and the control group [（0.32±0.10）%, （0.10±0.04）%, （0.17±0.07）%, P 〈 0.05, 0.01]; Th2 expression showed no significant difference between any two groups at each time point; Th1/Th2 at 6 hour after trauma was similar to that in the control group, which was gradually increased until to the peak value at 24 hour after trauma, and higher than the control group and trauma group at the same time point （22.49±12.64, 5.33±4.55, 4.78±3.15, P 〈 0.01）. CONCLUSION：（1）At the early phase of acute trauma （especially at 6 hour after trauma）, exogenous ADM shows a immune function modulation to adjust the proportion disequilibrium of Th1/Th2 by inhibiting Th1 predominant response. （2）Within the first 6 hours after acute trauma, ADM administration after trauma displays a better effect on Th1/Th2 balance than ADM administration before trauma.