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.
Wang
Qun-Li
QL
Department of Orthopedics and Traumatology, Nanfang Hospital, First Military Medical University, Guangzhou 510515, China.
Wang
Gang
G
Wang
Hua-Min
HM
Pei
Guo-Xian
GX
D000241:Adenosine / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D003402:Creatine Kinase / Q000378:metabolism; D003981:Diazoxide / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005121:Extremities / Q000098:blood supply* / Q000502:physiology; D019194:Ischemic Preconditioning; D008297:Male; D020011:Protective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control*
D020011:Protective Agents; D003402:Creatine Kinase; D000241:Adenosine; D003981:Diazoxide