Morphologic and functional renal impact of acute kidney injury after prolonged hemorrhagic shock in mice.

OBJECTIVE

Sparse data are available on renal consequences of hemorrhagic shock in mice. This study aimed to extend the current knowledge on functional and morphologic renal impact of hemorrhagic shock in mice and to determine its ability to stand as an accurate model of acute kidney injury.

DESIGN

In vivo study.

SETTING

University research unit.

SUBJECTS

C57/Bl6 mice.

INTERVENTIONS

A model of controlled hemorrhagic shock was adapted to determine the renal impact of hemorrhagic shock in mice.

MEASUREMENTS AND MAIN RESULTS

Renal functions and kidney morphology were followed up from 3 hrs to 21 days after hemorrhagic shock. When prolonged up to 2 hrs, hypotension (35 mm Hg mean arterial blood pressure) induced by temporary blood removal was responsible for an early and lasting increase in hypoxia-inducible factor-1α and kidney-inducible molecule-1 gene expression that paralleled acute tubular necrosis and renal failure. Two-hr hypotension induced an important but reversible decrease in glomerular filtration rate up to 6 days after hemorrhagic shock. Other renal dysfunctions included a renal loss of sodium, assessed by the increase in sodium excretion, and a decrease in urine concentration that persists up to day 21. Tissular damages prevailed in the outer medulla 2 days after hemorrhagic shock, being maximal at day 6. At day 21, renal healing was associated with epithelial recovery and a significant interstitial fibrosis.

CONCLUSIONS

Our data indicate that apparent recovery of renal function after acute kidney injury can mask persisting dysfunctions and tissular damages that could predispose to chronic kidney disease. Prolonged hemorrhagic shock in mice closely mimics renal effects induced by similar situation in humans, thus providing a useful tool to investigate pathophysiological mechanisms and protection strategies against acute kidney injury in situations such as hemorrhagic shock.