Intermittent Ischemic Preconditioning Protects Against Hepatic Ischemia-Reperfusion Injury and Extensive Hepatectomy in Steatotic Rat Liver

ABSTRACT

Background: Hepatic steatosis causes severe liver damage and has deleterious effects when associated with ischemia-reperfusion mechanisms. Ischemic preconditioning (IPC) protects lean liver against prolonged ischemia by improving micro-circulation and reducing lipid peroxidation. We investigated the effect of intermittent IPC on liver ischemia-reperfusion injury (IRI) and extensive hepatectomy in severe hepatic steatosis. Methods: Severe hepatic steatosis was performed by 12–14 weeks of choline-free diet in 108 Wistar rats. We induced 30-minute ischemia-reperfusion manipulations and extensive hepatectomy with or without prior IPC in steatotic livers and after 6 and 24 hours of reperfusion blood transaminases, and IL6, TNFα, NO and Lactate in blood and liver tissue were measured. Results: Steatotic rats subjected to hepatic ischemia-reperfusion alone after extensive hepatectomy, showed severe liver damage with significantly increased values of AST, ALT, TNFα and Lactate and significantly reduced IL6 and NO, while no one rat survived for more than 29 hours. On the contrary, steatotic rats subjected to intermittent IPC, 24 hours before ischemia-reperfusion, presented increased 30-day survival (67%), lower values of AST, ALT, TNFα and Lactate, and increased IL6 and NO levels. Simple and intermittent IPC manipulations, 1 hour before the IRI and extended hepatectomy, did not prolong survival more than 57 and 98 hours, respectively. Simple IPC, 24 hours before IRI and extended hepatectomy had the lowest possible survival (16.7%).Conclusions: Hepatic steatosis and IRI after major liver surgery largely affect morbidity and mortality. Intermittent IPC, 24 hours before IRI and extensive hepatectomy, presents higher 30-day survival and improved liver function parameters.

Keywords::

• simple ischemic preconditioning
• intermittent ischemic preconditioning
• ischemia-reperfusion injury
• extensive hepatectomy
• fatty liver disease
• steatotic liver

ACKNOWLEDGMENT

This study was funded by Scholarship – Grant by the Experimental Research Center ELPEN Pharmaceuticals (E.R.C.E). The authors would like to thank Maria Karamperi, Eleftheria Karampela and Kalliopi Tsarea for their help during the surgical procedures.

This experimental study was implemented at the Experimental Research Center of ELPEN (Athens, Greece) and was approved by Veterinary Authority of East Attica Prefecture (Protocol Ref. numbers: 1633 and 2659 directive 609/1986) and performed complying with the rules of experimentation and 3Rs (Replace, Reduce & Refine).

Declaration of interest:

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article. The authors reported no proprietary or commercial interest in any product mentioned or concept discussed in the article.

AUTHORS' CONTRIBUTIONS

N.S. contributed to animal experiments, data collection and analysis, writing and editing the article; T.K. contributed to conception, writing, critical revision and editing the article; K.A. and L.M. contributed to animal experiments and data analysis; M.D. contributed to laboratory data analysis and histopathology examinations; I.D.K. contributed to laboratory data collection and analysis; A.Z. contributed to animal experiments, animals care and anesthesia; A.P. contributed to animal experiments, data collection and analysis; G.K. contributed to critical revision and editing the article.