Hepatic (31)P‐magnetic resonance spectroscopy identified the impact of melatonin‐pretreated mitochondria in acute liver ischaemia‐reperfusion injury

Ko, Sheung‐Fat; Chen, Yi‐Ling; Sung, Pei‐Hsun; Chiang, John Y.; Chu, Yi‐Ching; Huang, Chung‐Cheng; Huang, Chi‐Ruei; Yip, Hon‐Kan

Acute liver ischaemia‐reperfusion injury (IRI), commonly encountered during liver resection and transplantation surgery, is strongly associated with unfavourable clinical outcome. However, a prompt and accurate diagnosis and the treatment of this entity remain formidable challenges. This study tested the hypothesis that (31)P‐magnetic resonance spectroscopy ((31)P‐MRS) findings could provide reliable living images to accurately identify the degree of acute liver IRI and melatonin‐pretreated mitochondria was an innovative treatment for protecting the liver from IRI in rat. Adult male SD rats were categorized into group 1 (sham‐operated control), group 2 (IRI only) and group 3 (IRI + melatonin [ie mitochondrial donor rat received intraperitoneal administration of melatonin] pretreated mitochondria [10 mg/per rat by portal vein]). By the end of study period at 72 hours, (31)P‐MRS showed that, as compared with group 1, the hepatic levels of ATP and NADH were significantly lower in group 2 than in groups 1 and 3, and significantly lower in group 3 than in group 1. The liver protein expressions of mitochondrial‐electron‐transport‐chain complexes and mitochondrial integrity exhibited an identical pattern to (31)P‐MRS finding. The protein expressions of oxidative stress, inflammatory, cellular stress signalling and mitochondrial‐damaged biomarkers displayed an opposite finding of (31)P‐MRS, whereas the protein expressions of antioxidants were significantly progressively increased from groups 1 to 3. Microscopic findings showed that the fibrotic area/liver injury score and inflammatory and DNA‐damaged biomarkers exhibited an identical pattern of cellular stress signalling. Melatonin‐pretreated mitochondria effectively protected liver against IRI and (31)P‐MRS was a reliable tool for measuring the mitochondrial/ATP consumption in living animals.