腺苷、三氮嗪及缺血预处理对缺血再灌注损伤肢体的作用

目的 探讨缺血预处理和腺苷（Ade)，二氮嗪（Dia)药物预处理对肢体缺血再灌注损伤的保护作用。方法 将66只SD大鼠随机分为6组：（1）正常对照组：（2）缺血再灌注（IR）组；（3）预处理10min组（IP10）；缺血10min后复流10min。重复3次；（4）预处理5min组（IP5）；缺血5min，复流5min，重复3次；（5）Ade预处理组；（6）Dia预处理组，对照组不作缺血处理，其余各组双后肢持续缺血4h，分别于再灌注2、24h检测胫前肌的单收缩，强直收缩力及血清肌酸磷酸激酶（CPK）含量。结果 （1）IP5及Ade组在再灌注2h及24h较IR组的胫前肌单收缩力显著增加，而与对照组接近，（2）IP10组在再灌注2h时的保护作用不明显，在24h时有一定的保护作用。但弱于Ade及IP5组。（3）Dia组胫前肌的单收缩及强直收缩力在再灌注2h时较IR组降低，而在24h单收缩力显著升高，各预处理组对胫前肌的强直收缩力没有明显的保护作用，IP5，IP10及Ade组在再灌注2和24h时，而Dia组只在再灌注24h时血清CPK显著低于IR组。结论 缺血预处理和腺苷对肢体的缺血再灌注损伤有保护作用；Dia有延迟保护作用；IP5的作用优于IP10组；腺苷预处理可以取得与缺血预处理相当的效果。

Effect of pretreatment with adenosine, diazoxide or ischemic preconditioning on ischemia- reperfusion injury in the limbs of rats.

OBJECTIVE: To study the effect of ischemic preconditioning (PC) and pharmacological preconditioning with adenosine or diazoxide on ischemia-reperfusion (IR) injury in the limbs of rats. METHODS: According to different treatment received before ischemic-reperfusion injury, 66 SD rats were divided into 6 groups including a normal control and a ischemia-reperfusion control group, IP10 group in which the rats received 10-min ischemia followed by 10-min interval for reperfusion for 3 times before IR, IP5 group in which the rats were subjected to 5-min ischemia with 5-min reperfusion intervals for 3 times before IR, adenosine (Ade) pretreatment group and diazoxide (Dia) pretreatment group. Except the normal control group, which consisted of 6 rats, each group contained 12 rats, and IR injury was induced by blocking the blood flow in bilateral limbs for 4 h, followed by reperfusion for 2 or 24 h when twitch and spastic contractility of the tibialis anterior muscle and serum creatine phosphokinase (CPK) were measured. RESULTS: In IP5 and Ade pretreatment group, the twitch tension of the tibialis anterior muscle of the rats was significantly enhanced after 2 and 24 h of reperfusion, achieving the level of the normal control. The twitch tension was also enhanced in rats of IP10 group at 24 h, but at 2 h, though with less effectiveness than that in IP5 and Ade group. Dia pretreatment reduced twitch and tetanic contraction forces of the tibialis anterior muscle after 2 h of reperfusion, but obviously improved twitch tension at 24 h. Improvement in the tetanic tension, however, was seen in none of the groups. Serum CPK of IP5, IP10 and Ade groups after 2 and 24 h while Dia at only 24 h of reperfusion was obviously lower than that of IR group. CONCLUSIONS: Ischemic and Ade preconditioning can protect the limbs of rats from ischemia-reperfusion injury, and Dia has delayed protective effect. IP5 is superior than IP10 and Ade PC can produce similar effect to that of ischemic PC.