Cold preservation-warm reoxygenation increases hepatocyte steady-state Ca(2+) and response to Ca(2+)-mobilizing agonist

• Published in: American journal of physiology: Gastrointestinal and liver physiology 2001-09, Vol.281 (3), p.G809-G815
• Main Authors: Elimadi, A, Haddad, P S
• Format: Article
• Language: English
• Subjects: 3-Iodobenzylguanidine - pharmacology; Adenosine Triphosphate - metabolism; Adenosine Triphosphate - pharmacology; Animals; Calcium - metabolism; Cell Survival - drug effects; Cell Survival - physiology; Cold Temperature; Cytoprotection; Dose-Response Relationship, Drug; Hepatocytes - cytology; Hepatocytes - drug effects; Hepatocytes - metabolism; Inositol 1,4,5-Trisphosphate - pharmacology; Intracellular Fluid - metabolism; Male; Microscopy, Fluorescence; Mitochondria - drug effects; Mitochondria - metabolism; Oxygen - metabolism; Oxygen - pharmacology; Rats; Rats, Sprague-Dawley; Temperature
• ISSN: 0193-1857
• DOI: 10.1152/ajpgi.2001.281.3.g809

Although the role of Ca(2+) in liver transplantation injury has been the object of several studies, direct evidence for alterations in intracellular Ca(2+) homeostasis after cold preservation-warm reoxygenation (CP/WR) has never been presented. We thus investigated the effects of CP/WR on steady-state Ca(2+) and responses to a Ca(2+)-mobilizing agonist. Isolated rat hepatocytes were suspended in University of Wisconsin solution, stored at 4 degrees C for 0, 24, and 48 h, and reoxygenated at 37 degrees C for 1 h. Cytosolic Ca(2+) was measured in single cells by digitized fluorescence videomicroscopy. CP/WR caused a significant increase in steady-state cytosolic Ca(2+), which was inversely proportional to cell viability. Pretreatment of hepatocytes with an agent that protects mitochondrial function attenuated the increase in steady-state cytosolic Ca(2+) and improved hepatocyte viability. Ca(2+) responses to the purinergic agonist ATP also increased significantly as a function of cold storage time. This increase was related to an increase in the size of inositol 1,4,5-trisphosphate-sensitive Ca(2+) stores and subsequent capacitative Ca(2+) entry. Thus CP/WR significantly perturbs steady-state hepatocellular Ca(2+) and responses to Ca(2+)-mobilizing agonists, which may contribute to hepatocyte metabolic dysfunction observed after CP/WR.