Kivonat:
Previous experimental data suggest that steroids might have
protective effects during hypoxic/ischemic injury of various
organs. In this study, the association between dexamethason
(Dexa) treatment and the anti-apoptotic SGK-1 was tested in
ischemic renal injury. In vitro, HK-2 cells were exposed to 24 h
hypoxia, and the effect of Dexa incubation on SGK-1 expression /
activation and on cell death was studied. In an in vivo rat
model of unilateral renal IR, animals were treated with Dexa,
and serum renal function parameters, tissue injury and SGK-1
expression and localization were examined after different
reperfusion times (2 h, 4 h and 24 h). Dexa at a dose of 2 mg/L
exerted a protective effect on cell survival assessed by LDH
release and vital staining paralleled by marked up-regulation of
SGK-1. In rats, 2 mg/kg Dexa treatment 24 h prior to ischemia
resulted in less severe tissue injury and ameliorated urea
nitrogen levels 24 h after reperfusion. Furthermore, SGK-1
expression and phosphorylation were higher in Dexa animals
demonstrated by Western blot and immunofluorescence technique.
Our results provide novel data on the signalling mechanism of
Dexa under hypoxia / ischemia and further support that Dexa
emerges as an attractive pharmacological agent for the
prevention of ischemic injury.