The Nutritional Status Modulates Preservation-Reperfusion Injury in Rat Fatty Liver
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The Nutritional Status Modulates Preservation-Reperfusion Injury in Rati
Journal of Surgical Research 127, 190196 (2005)doi:10.1016/j.jss.2005.02.018
002 2ile PG infusion had no effect. Glucose supplemen-tion did not affect portal pressure, which, in con-st, was reduced in livers receiving PG. Finally, allatments lowered oxidative injury.Conclusions. Preservation injury in fatty liver iseatly related to nutritional status. Energetic sub-ate supplementation may represent a clinically fea-
blood flow is greatly reduced after transplantation offatty livers as the result of the narrowed sinusoidallumen, which is compressed by the swollen fat-loadedhepatocytes and partially or completely obstructed bycell debris and platelets and leukocytes adherent to theendothelium . Thus, it is not surprising that sub-stances with vasodilator and antiinflammatory proper-ties, such as prostaglandins, have been found to beprotective in animal models of fatty liver transplanta-tion [4, 5].
However, other evidences indicate that hepatocyte
To whom correspondence and reprint requests should be ad-ssed at Dipartimento di Medicina Interna, Cardioangiologia,atologia, University of Bologna, Policlinico SantOrsola, Via Al-toni 15, 40138 Bologna, Italy. E-mail: firstname.lastname@example.org.
1902-4804/05 $30.00005 Elsevier Inc. All rights reserved.Fatty L
olo Caraceni,*,,1 Marco Domenicali,*, Anna Maria PAlessandro Principe,*, Giuseppe Palasciano,
*Department of Internal Medicine, Cardioangiology, and Hepatologpplied Research (C.R.B.A.), University of Bologna, Bologna, Italy; an
of Bari, Ba
Submitted for publicat
Background. Microcirculation disturbances are es-ntial factors of preservation injury in fatty liver.wever, hepatocyte injury is alsomarkedly excessivefatty liver resulting, at least in part, from energytabolism impairment and oxidative stress. Thus,is study aimed to determine whether nutritional sta-s influences preservation injury in fatty liver andether energetic substrate supplementation, alonewith a vasodilator, is protective.Materials and methods. Normal or fatty livers in-ced by a choline-deficient diet were isolated fromand fasted rats, preserved in University of Wiscon-solution at 4C for 18 h, and then reperfused with
ebsHenseleit solution at 37C for 120 min. Fastedts with fatty liver were also treated as follows: (1)ucose supplementation: rats had access to a glucoselution for 18 h prior procurement; (2) ProstaglandinG): alprostadil was continuously infused duringperfusion; (3) Combined treatment: Glucose supple-ntation PG.Results. Fasting-induced liver injury was signifi-ntly greater in fatty than normal liver. In fatty liversm fasted rats, all treatments reduced the alanineinotransaminase release. Hepatic oxygen consump-n improved in the glucose and glucose PG groups,ver
osa,*, Elisabetta Maiolini,* Ignazio Grattagliano,ranco Trevisani,* and Mauro Bernardi*,
University of Bologna, Bologna, Italy; Center for BiomedicalDepartment of Internal Medicine and Public Health, UniversityItaly
October 28, 2004
le protective strategy and a multistep approachding vasodilators could offer further benefit by act-g on different pathogenetic mechanisms. 2005evier Inc. All rights reserved.
Key Words: fatty liver; experimental liver transplan-tion; preservation injury; reperfusion injury; nutri-nal status; prostaglandins.
Fatty liver is the most frequent alteration of the livernd in the general population and its prevalence
aches about 25% of the potential donors for ortho-pic liver transplantation and living donor liver trans-antation. The presence of fatty degeneration reducese tolerance of the liver to the ischemia-reperfusionjury invariably associated with these surgical proce-res, leading to higher mortality and postoperativemplication rates. Thus, albeit the persistent short-e of donor organs, most centers do not transplanters with moderate-massive fatty infiltration .Impaired microcirculation has been proposed as they event in the pathogenesis of preservation-perfusion injury in steatotic livers . The sinusoidal
injury is also markedly excessive in fatty liver exposedtomsuintio
of the hepatocytes, without evidence of inflammation and/or fibrosis. Triglycerides are the main component of accumulated lipidswitoccintwa
191CARACENI ET AL.: PRESERVATION INJURY IN FATTY LIVERcold preservation compared to that observed in nor-al organs . Several potential events have beenggested as mediators of this parenchymal cell injurycluding oxidative stress , mitochondrial dysfunc-n , and energy metabolism impairment .The preexisting nutritional status is a major deter-inant of hepatocyte injury associated with ischemia-perfusion . In normal livers, it is universally ac-pted that fasting exacerbates warm ischemic injury, 10]. Less homogenous results have been obtained ifrmal livers are exposed to cold ischemia; when fast-g is prolonged up to 4 days, the starved livers appearpable of tolerating the transplant procedure betteran do livers obtained from fed donors [11, 12]. Nev-theless, preharvesting nutritional repletion by glu-se supplementation improves survival and livernction in both fasted and fed animals [13, 14].Conversely, the data on the effect of nutritional sta-s in fatty livers subjected to ischemia-reperfusion arery limited. We previously reported that the preexist-g nutritional status of the animal adversely affectsrm ischemia-reperfusion injury in fatty livers much
ore than it does in normal livers . A preliminaryport suggested that fasting rats with fatty liver for 4ys reduces early reperfusion injury after cold isch-ia likely by suppressing Kupffer cell function .wever, long-term starvation is not applicable in the
tting of clinical transplantation and the effect of aorter period of fasting has never been tested thus far.us, no clear data exist on the relation between fattyer, preservation injury, and nutritional status.Therefore, the aim of this study was to compare in aodel of isolated perfused rat liver the influence ofimal starvation on cold ischemia-reperfusion injuryperienced by normal and fatty liver induced by aoline-deficient diet. Furthermore, since the alter-ion of the nutritional status is a common condition oftential donors staying in intensive care units forveral days and the beneficial effect of a nutritionalpport has been already demonstrated in normal liv-s exposed to cold ischemia [13, 14], experiments wereo designed to determine whether administration ofergetic substrates, alone or with a vasodilator, isotective against preservation injury in fatty liverm fasted rats.
MATERIALS AND METHODS
Animals and Induction of Fatty Liver
Male Sprague Dawley rats (Charles River, Calco, LC, Italy),ighing 150175 g, were allowed to acclimate to the animal quar-s and were given free access to a standard chow diet and water foreek. Then, rats were fed a choline-deficient diet (Dyets Inc.,
thlehem, PA) for an additional 5 days. With this procedure, theer of rats fed the choline-deficient diet presented a moderateatosis, predominantly macrovesicular and involving about 50-60%h an increased molar percentage of palmitic and oleic acids as iturs in fatty liver developing in humans for an excessive dietaryake of carbohydrates . Prior to sacrifice, the animal weights similar in the two groups ranging between 230 and 280 g.All procedures involving rats were conducted according to theidelines for the care and use of laboratory animals approved by ourtitution.
Procurement and Preservation of the Liver
The rats were anesthetized with enflurane (Abbott Laboratories,icago, IL); the abdomen was opened with a midline incision andportal vein was cannulated with a 16-G angiocath. The liver was
shed out with 20 ml of the University of Wisconsin (UW) solution4C and then immediately removed. After 18 h of preservation inUW solution at 4C, all livers were exposed to room temperature
a Petri dish for 15 min prior to reperfusion to mimic the period ofarming during surgical implantation in vivo. The organs weren rinsed with 10 ml of a KrebsHenseleit bicarbonate (KHB)ution and connected to the perfusion circuit.
Isolated Perfused Rat Liver Model
The livers were perfused in a non-recirculating fashion by using aistaltic pump for 120 min at 37C with a KHB buffer containingM glucose and 0.5% serum bovine albumin within a thermostat-
lly controlled plexiglas cabinet designed to perform two perfusionsultaneously (Ditta Disa, Milan, Italy) . The KHB solution wasosed to a gas mixture of 95% O2 and 5% CO2 in a pressuredmbrane oxygenator, which generated a partial pressure of O2ater than 500 mm Hg. The organs were initially perfused at a flowe of 0.5 ml/min/g liver and then increased progressively up to 3.0/min/g liver in a 5-min period to avoid barotrauma. The portalssure was continuously monitored through a three-way stopcockced before the portal vein cannula and expressed as cm H2O.mples were taken from a portal inflow port and from the effluentfusate for measurement of the alanine aminotransaminase (ALT)el and oxygen consumption. In most of the experiments, liversue was also collected for the biochemical determinations beforelantation (basal conditions) and at the end of r