RESUMO
The uptake of hyaluronic acid (HA) was used to assess preservation damage to sinusoidal endothelial cells (SEC) during cold storage and subsequent normothermic reperfusion of rat livers. After 8, 16, 24, and 48 h storage in University of Wisconsin (UW) solution, livers were gravity-flushed via the portal vein with a standard volume of cold UW solution containing 50 micrograms/l HA. The effluent was collected for analysis of HA, aspartate aminotransferase (AST), and lactate dehydrogenase (LDH). The mean uptake of HA at 0 h was 59.1% +/- 4.6% (mean +/- SEM). After 8 h of storage, HA uptake was similar (55.5% +/- 7.3%), whereas after 16 h of storage it was reduced to 34.7% +/- 5.8%. At 24 and 48 h of storage, no uptake of HA was found. In a second series of experiments, livers were stored in UW solution and subsequently reperfused for 90 min with a Krebs-Henseleit solution (37 degrees C) in a recirculating system containing 150 micrograms/l HA. Following 8 h of storage, 34.6% +/- 8.0% of the initial HA concentration was taken up from the perfusate. After 16 and 24 h of storage, no uptake of HA was found. The results of this study indicate that damage to SEC occurs progressively during storage, leading to zero uptake of HA by the rat livers at 24 h of cold ischemia time. Additional reperfusion injury to the SEC was demonstrated by the reduced ability of the SEC to take up HA following normothermic reperfusion. The uptake of exogenous HA in preserved livers, used as a tool to assess SEC injury, enables the detection of early preservation damage.
Assuntos
Temperatura Baixa/efeitos adversos , Ácido Hialurônico/metabolismo , Fígado/metabolismo , Soluções para Preservação de Órgãos , Preservação de Órgãos , Traumatismo por Reperfusão/metabolismo , Adenosina , Alopurinol , Animais , Biomarcadores , Endotélio/patologia , Feminino , Glucose , Glutationa , Insulina , Isquemia , Fígado/irrigação sanguínea , Fígado/patologia , Preservação de Órgãos/métodos , Oxigênio/farmacologia , Rafinose , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Temperatura , TrometaminaRESUMO
A continuous intramuscular oxygen tension sensor was compared, with transcutaneous oximetry and laser Doppler flowmetry, during periods of arterial flow alterations in an isolated hindlimb model in the pig. The intramuscular oxygen tension sensor correlated well with bloodflow and was superior to the other two methods.