Ischemia With Preconditioning in Wistar Rats Maintains Mitochondrial Respiration, Even With Mild Hepatocellular Disturbance.

INTRODUCTION: In hepatectomy or liver transplantation, preconditioning is a procedure indicated to protect the organ from ischemia-reperfusion injury (I-R).

OBJECTIVE: Evaluate the effect of preconditioning after hepatic I-R in Wistar rats, through mitochondrial respiration, liver histology, and profile.

METHOD: Twenty male Wistar rats, weighing on average 307.1 g, were anesthetized with sodium thiopental (25 mg/kg) intravenously and xylazine hydrochloride (30 mg/kg) intramuscularly. The animals were divided into 2 groups: the preconditioning group (PCG), which contained 10 animals, and the hepatic pedicle was isolated and submitted to clamping with microvascular clamp (10 minutes of ischemia and 10 minutes of reperfusion, followed by 30 minutes of ischemia and 30 minutes of reperfusion); and the simulated operation group (SOG), which contained 10 animals submitted to manipulation of the hepatic pedicle and observation for the same length of time, with blood collected for transaminase dosage measurements, and liver biopsy for evaluation of mitochondrial respiration and histologic liver analysis and after sacrificed under anesthesia. The project was approved by the Ethics Committee on Animal Experimentation CEEA/UNICAMP under protocol number 3905-1.

RESULT: The PCG mitochondria showed the same respiration level as the SOG, when stimulated with the addition of adenosine diphosphate or carbonyl cyanide p-trifluoromethoxyphenylhydrazone. In the respiratory control ratio and resting of velocity of respiration the groups behaved in a similar way. The PCG presented high aspartate and alanine transaminases (P < .03) and about 60% of sinusoidal congestion and venous congestion in the histologic analysis when compared with SOG.

CONCLUSION: We found that ischemia with preconditioning in Wistar rats can lead to mild histologic and biochemical dysfunction without leading to impairment of mitochondrial respiration.