Post-ischaemic administration of hyperosmolar mannitol enhances erythrocyte trapping in outer medullary vasculature in the rat kidney.

Mannitol is widely used as a therapeutic agent in the management of acute renal failure. We sought to determine whether mannitol influences the trapping of red blood cells (RBCs) in renal microvasculature, as measured from the distribution of 51Cr-labelled RBCs, in the rat kidney after ischaemia. The results indicate that administration of hyperosmolar mannitol after an ischaemic insult increases RBC trapping in the outer renal medulla in a dose-dependent manner. This was found to occur even though parameters of nephron function were unaffected or even improved.