Delivery of the Bioactive Gas Hydrogen Sulfide During Cold Preservation of Rat Liver: Effects on Hepatic Function in an Ex vivo Model Cecilia L. Balaban, Joaquín V. Rodriguez, and Edgardo E. Guibert Centro Binacional (Argentina-Italia) de Investigaciones en Criobiología Clínica y Aplicada (CAIC), Universidad Nacional de Rosario, Rosario, Santa Fe,Argentina Abstract: The insults sustained by transplanted livers (hepatectomy, hypothermic preservation, and normother- mic reperfusion) could compromise hepatic function. Hydrogen sulfide (H2S) is a physiologic gaseous signaling molecule, like nitric oxide (NO) and carbon monoxide (CO). We examined the effect of diallyl disulfide as a H2S donor during hypothermic preservation and reperfusion on intrahepatic resistance (IVR), lactate dehydrogenase (LDH) release, bile production, oxygen consumption, bro- mosulfophthalein (BSP) depuration and histology in an isolated perfused rat liver model (IPRL), after 48 h of hypothermic storage (4°C) in University of Wisconsin solution (UW, Viaspan). Livers were retrieved from male Wistar rats. Three experimental groups were analyzed: Control group (CON): IPRL was performed after surgery; UW: IPRL was performed in livers preserved (48 h—4°C) in UW; and UWS: IPRL was performed in livers preserved (48 h—4°C) in UW in the presence of 3.4 mM diallyl dis- ulfide. Hypothermic preservation injuries were manifested at reperfusion by a slight increment in IHR and LDH release compared with the control group. Also, bile pro- duction for the control group (1.32 mL/min/g of liver) seemed to be diminished after preservation by 73% in UW and 69% in UW H2S group at the end of normothermic reperfusion. Liver samples analyzed by hematoxylin/eosin clearly showed the deleterious effect of cold storage process, partially reversed (dilated sinusoids and vacuolization attenuation) by the addition of a H2S delivery compound to the preservation solution. Hepatic clearance (HC) of BSP was affected by cold storage of livers, but there were no noticeable differences between livers preserved with or without diallyl disulfide. Meanwhile, livers preserved in the pres- ence of H2S donor showed an enhanced capacity for BSP uptake (kACON = 0.29 min -1 ;kAUW = 0.29 min -1 ;kAUWS = 0.36 min -1 ). In summary, our animal model suggests that hepatic hypothermic preservation for transplantation affects liver function and hepatic depuration of BSP, and implies that the inclusion of an H2S donor during hypoth- ermic preservation could improve standard methods of preparing livers for transplant. Key Words: Liver— Organ preservation—Liver function tests—Drug kinetics. Orthotropic liver transplantation is an effective therapeutic modality for the treatment of end-stage liver disease. A prerequisite of successful liver trans- plantation is that the graft must function immedi- ately, as no satisfactory method for long-term hepatic support is available at present. This consideration demands extra attention to preserve maximum viability during the ischemia period between the removal of the donor organ and reimplantation. Suc- cessful liver preservation has been achieved clinically up to 20 h (1). In experimental procedures, this time has been extended up to 48 h (2). The insults sus- tained by the transplanted livers (hepatectomy, hypothermic preservation, and normothermic reper- fusion) could compromise hepatic function. Simple tests of active metabolism such as oxygen consump- tion and bile production, among others, could be used to assess liver function. As hydrogen sulfide (H2S) was included in the gasotransmitter classification as a powerful gaseous signaling molecule along with carbon monoxide and doi:10.1111/j.1525-1594.2011.01256.x Received March 2011. Address correspondence and reprint requests to Dr. Edgardo E. Guibert, Centro Binacional de Criobiología—Universidad Nacio- nal de Rosario,Avda.Arijón 28 bis, S2011BXN Rosario,Argentina. E-mail: eguibert@fbioyf.unr.edu.ar Presented in part at the 6th Latin American Congress of Artifi- cial Organs and Biomaterials, held August 17–20, 2010 in Gramado, Rio Grande do Sul, Brazil. Artificial Organs 35(5):508–515, Wiley Periodicals, Inc. © 2011, Copyright the Authors Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc. 508