Renal function and cortical (Na(+)+K(+))-ATPase activity, abundance and distribution after ischaemia-reperfusion in rats.
The effects of ischaemic injury and reperfusion on renal function, cortical ATP content, alkaline phosphatase activity and (Na(+)+K(+))-ATPase activity and abundance in cortical homogenates and isolated basolateral and apical membranes were examined. Rats were submitted to 5 or 40 min of right renal artery occlusion and 60 min of reperfusion. Renal function of the ischaemic-reperfused kidney was studied by conventional clearance techniques. Our results show that 1 h of reperfusion after a short period of renal ischaemia (5 min) allows the complete restoration of the biochemical features of cortical cells and functional properties of the injured kidney. A longer period of ischaemia, such as 40 min, followed by 1 h of reperfusion showed functional and biochemical alterations. ATP recovered from 26% after 40 min of ischaemia to 50% of control values after 1 h reperfusion. However, renal function was strongly impaired. Brush border integrity was compromised, as suggested by AP excretion and actin appearance in urine. Although total cortical (Na(+)+K(+))-ATPase activity was not different from controls, its distribution in isolated apical and basolateral membranes was abnormal. Remarkably, we detected an increase in alpha-subunit protein abundance that may suggest that (Na(+)+K(+))-ATPase synthesis is promoted by ischaemia-reperfusion. This increase may play an important role in the pathophysiology of ischaemic acute renal failure.
Coux
Gabriela
G
Farmacología, Departamento de Ciencias Fisiológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CONICET, Suipacha 531, Rosario, Argentina. gcoux@fbioyf.unr.edu.ar
Trumper
Laura
L
Elías
M Mónica
MM
D000199:Actins / Q000652:urine; D058186:Acute Kidney Injury / Q000209:etiology; D000255:Adenosine Triphosphate / Q000032:analysis / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000652:urine; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D007511:Ischemia / Q000150:complications / Q000201:enzymology* / Q000652:urine; D007668:Kidney / Q000098:blood supply* / Q000502:physiology; D007672:Kidney Cortex / Q000201:enzymology*; D008297:Male; D008871:Microvilli / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology; D013997:Time Factors
D000199:Actins; D000255:Adenosine Triphosphate; D000469:Alkaline Phosphatase; D000254:Sodium-Potassium-Exchanging ATPase