IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
artículos
Título:
Ischemia/Reperfusion in rat renal cortex: vesicle leakiness and Na+, K+-ATPase activity in membrane preparations.
Autor/es:
GABRIELA COUX, M. MÓNICA ELÍAS, LAURA TRUMPER
Revista:
NEPHROLOGY DIALYSIS TRANSPLANTATION
Editorial:
Oxford University Press
Referencias:
Año: 2008
ISSN:
0931-0509
Resumen:
BACKGROUND: Despite the central role of Na+, K+-ATPase (NKA) in ischemic renal injury(IRI), cortical NKA activity values during renal ischemia remain controversial. In this study,we explore why cortical NKA activity shows such behaviour during ischemia in rats.METHODS: Ischemia was induced by unilateral renal artery clamping (40 min, I) followed ornot by reperfusion (60 min, IR). NKA α and β subunits abundance was analyzed by Westernblot. We studied the NKA detergent (SDS) enzymatic activation in isolated membranepreparations from control and ischemic kidneys. RESULTS: NKA activity was diminished inI cortical homogenates (C= 9.3 ± 1.1, I=4.7 ± 1.1* μmol Pi/h.mg Prot, n=4-6,*p<0.05 vs C).This was rapidly recovered after reperfusion (IR= 9.9 ± 1.2 μmol Pi/h.mg Prot). α subunitlevels were increased, while β subunit was unchanged. At SDS 0.9 mg/ml (maximal detergentactivation) the activities were indistinguishable (C= 90.5 ± 2.2, I= 91.4 ± 15.1 μmol Pi/h.mgProt). The analysis of detergent activation of NKA activity is widely used to estimatemembrane leakiness in plasma membrane preparations. Our results suggest a higherpopulation of sealed impermeable vesicles in preparations from ischemic renal tissue.CONCLUSION: The well known effect of ischemia on renal cell cytoskeleton could explainthe observed changes in the leakiness of membrane vesicles.