Effects of Long-Term Hepatic Ischemia-Reperfusion Injury on the Function of P-glycoprotein in vivo in Rats

Abstract

-PURPOSE: Ischemia-reperfusion injury is a common complication in liver surgery with oxidative stress related graft failure as a potential complication. The oxidative stress could affect hepatic drug transporters such as P-glycoprotein, which is crucial in the hepatic clearance of certain immunosuppressant drugs. Thus,, it is important to study its function after ischemia-reperfusion injury in vivo. Rhodamine 123 is a fluorescent substrate of P-glycoprotein and its hepatic disposition can be visualized using multiphoton microscopy in vivo using anaesthetized animals. The aim of this study was to investigate the effect of long-term ischemia-reperfusion injury on P-glycoprotein function in hepatocytes using in vivo multiphoton microscopy. METHODS: Localized ischemia was induced for 1 hour in rats. The liver was reperfused for 4, 24, 48 hours or 1 week, where-after rhodamine 123 was injected intravenously. Multiphoton microscopy imaged the liver and bile was collected continuously up to 6 hours following drug administration. The liver was harvested for histology andprotein expression of Pglycoprotein. RESULTS: Ischemia-reperfusion injury resulted in extensive liver damage, inflammatory cell infiltration and apoptosis in the midzonal and centrilobular regions of the liver acinus. P-glycoprotein protein expression decreased. Cellular concentration of rhodamine 123 increased as visualized by multiphoton microscopy, which was confirmed with decreased excretion of rhodamine 123 in collected bile. CONCLUSIONS: This study showed reduced function of P-glycoprotein in ischemia-reperfusion injury as reflected by decreased biliary excretion of Rhodamine 123, as well as reduced protein expression of the transporter. Multiphoton microscopy could be used to visualize and quantitate the intracellular levels of rhodamine 123. These findings stipulate the importance of using multiphoton microscopy to understand transmembrane drug flux and reflect on careful drug dosing after hepatic surgery.

Effects of Pringle maneuver and partial hepatectomy on the pharmacokinetics and blood–brain barrier permeability of sodium fluorescein in rats

“…Recent studies (Hashimoto and Sanjo, 1997;Ikemura et al, 2009;Parasrampuria et al, 2012;Shaik and Mehvar, 2011;Thorling et al, 2014;Tian et al, 2005aTian et al, , 2005b have shown that IR injury or Hx alters the disposition of drugs. In agreement with these studies, our current investigation showed that IR alone or in combination with Hx (HxIR) would change the systemic pharmacokinetics of FL (...…”

Causes and Consequences of Variability in Drug Transporter Activity in Pediatric Drug Therapy

“…One of the proposed mechanisms is a modification of mRNA expression induced by proinflammatory cytokines such as IL‐6, IL‐1β, and TNFα . Endotoxin‐induced down‐regulation of drug transporters is another proposed mechanism as well as oxidative stress …”

“…[110][111][112] Endotoxin-induced down-regulation of drug transporters is another proposed mechanism 110,112 as well as oxidative stress. 113,114 Inflammatory bowel diseases are known to induce changes in the intestinal epithelium, such as alteration of permeability, 115 and to be associated with an increase in proinflammatory agents. [116][117][118][119][120] A study conducted in children has analyzed the impact of Crohn disease (CD) on the expression of P-gp.…”