Microvascular research
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Microvascular research · Aug 2008
The influence of selenium substitution on microcirculation and glutathione metabolism after warm liver ischemia/reperfusion in a rat model.
Ischemia/reperfusion (I/R) injury is a variable yet unavoidable complication in liver surgery and transplantation. Selenium-dependent glutathione-peroxidases (GPx) and selenoproteins function as antioxidant defense systems. One target in preventing I/R injury is enhancing the capacity of endogenous redox defense. ⋯ In liver tissue, selenium supplementation caused an increase in the amount of total and reduced glutathione without changes in oxidized glutathione. This effect is likely mediated by selenite itself and selenoprotein P rather than by modulating GPx activity. We were able to show that selenite substitution has an immediate protective effect on I/R injury after warm hepatic ischemia by acting as a radical scavenger and preserving the antioxidative capacity of the liver.
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Microvascular research · Aug 2008
Change in plasma volume from a state of hyper-, normo- or hypovolemia with or without noradrenalin infusion in the rat.
Fluid substitution is important in critically ill patients to maintain normovolemia, but there is always a risk that the treatment is too aggressive resulting in fluid overload, or is insufficient with maintenance of hypovolemia. The present study on the rat aims at evaluating the change in plasma volume after 2.5 h from a state of hyper- and hypovolemia. The analysis was made without and with noradrenalin infusion, based on the fact that noradrenalin infusion is a common drug to maintain an adequate arterial pressure, and noradrenalin may induce transcapillary filtration. ⋯ We conclude that hypervolemia induces plasma volume loss, which is aggravated by noradrenalin infusion. The compensatory absorption effect after hemorrhage is counteracted by noradrenalin. The results can be explained by differences in hydrostatic capillary pressure via alterations in arterial and venous pressure, according to the 2-pore theory of transcapillary fluid exchange.