Autofluorescence spectroscopy of rat liver during experimental transplantation procedure. An approach for hepatic metabolism assessment.

Ischemia-reperfusion injury, a major cause of organ metabolic alterations and consequent dysfunction in liver transplantation, could be overcome by optimizing organ preservation procedures. The potential of autofluorescence analysis was investigated with the aim to define parameters suitable for in vivo monitoring tissue functionality. Spectrofluorometric analysis was performed on explanted rat livers during cold storage, under standard (4 degrees C University of Wisconsin medium for 20 h) and purposely damaging (4 degrees C Eurocollins medium for 20, 43 and 72 h) preservation conditions, and reperfusion (rewarming-reoxygenation).

Apoptosis vs. necrosis: glutathione-mediated cell death during rewarming of rat hepatocytes.

Hypothermia induces injury in its own right, but the mechanisms involved in the cell damage are still unclear. The aim of this study was to test the effects that glutathione (GSH) depletion induces on cell death in isolated rat hepatocytes, kept at 4 degrees C for 20 h, by modulating intracellular GSH concentration with diethylmaleate and buthionine sulfoximine (DEM and BSO). Untreated hepatocytes showed Annexin V stained cells (AnxV(+)), scarce propidium iodide stained cells (PI(+)) and presented a low level of lactate dehydrogenase (LDH) leakage after 20 h at 4 degrees C and rewarming at 37 degrees C.

Exogenous melatonin enhances bile flow and ATP levels after cold storage and reperfusion in rat liver: implications for liver transplantation.

Although the use of melatonin in the transplantation field has been suggested, it has not been previously tested in a liver cold-storage model. We used a rat liver model to study (a) the dose-dependent effect of melatonin on bile production, and (b) the potential of melatonin to improve liver function after cold-storage. Male Wistar rats were perfused with Krebs-Henseleit bicarbonate buffer (KHB) at 37 degrees C without or with 25, 50, 100 and 200 microM melatonin.

Autofluorescence properties of isolated rat hepatocytes under different metabolic conditions.

The contribution of endogenous fluorophores - such as proteins, bound and free NAD(P)H, flavins, vitamin A, arachidonic acid - to the liver autofluorescence was studied on tissue homogenate extracts and on isolated hepatocytes by means of spectrofluorometric analysis. Autofluorescence spectral analysis was then applied to investigate the response of single living hepatocytes to experimental conditions resembling the various phases of the organ transplantation. The following conditions were considered: 1 h after cells isolation (reference condition); cold hypoxia; rewarming-reoxygenation after cold preservation.

Stem cell recruitment and liver de-differentiation in MMTV-neu (ErbB-2) transgenic mice.

The liver of tumor-bearing hosts manifests fetal phenotypes. We investigated the expression of differentiation markers on the liver in MMTV-neu (ErbB-2) transgenic mice, in the period from incipient neoangiogenesis to lung metastatization. We report AFP expression by hepatocytes in all lobular zones, CD34 cell arrest and subsequent hemopoiesis in periportal and mid-zone areas, oval-like cells (CD34+, CK19+, AFP+) and ductular reaction in portal tracts, portal CK19+ and GGT+ hepatoblast-like cells, and midzonal large dysplastic hepatocytes.

In situ detection of reactive oxygen species and nitric oxide production in normal and pathological tissues: improvement by differential interference contrast.

Reactive oxygen species (ROS), among which nitric oxide (NO) is currently included, play a plethora of (patho)physiological roles. Harman's free radical theory of aging put forth over 40 years ago received full support since then. A nitric oxide hypothesis of aging recently proposed by McCann, is very likely to be the object of widespread investigation in the near future.