EFFECT OF ANTICOAGULATION UPON NEPHRON OBSTRUCTION IN EXPERIMENTAL ACUTE ISCHEMIC RENAL-FAILURE - A MORPHOLOGICAL-STUDY

Ischaemic-reperfusion injury as a model of acute renal failure (ARF) r esults in increased macromolecular permeability, tubular obstruction, and renal oedema. To investigate the role for coagulation in this mode l, anticoagulated and saline-pretreated rats were subjected to 60 min unilateral renal artery occlusion (RAG). After 15 min of reflow, speci mens were collected for electron and light microscopic examination. Mo rphometry was employed to study podocyte changes and Bowman's space di latation as measures of increased permeability and tubular obstruction , respectively. After 15 min of reflow, Bowman's space increased signi ficantly and the podocytes were markedly widened and flattened. Rats p retreated with heparin or warfarin showed less widening of Bowman's sp ace than saline-treated rats, whereas no significant difference was se en regarding the podocyte changes. In saline-treated rats, fibrin-posi tive material was seen in the tubules but not in the urine sediments c ollected after 90 min of reflow, either due to fibrinolysis or poor ur inary elimination. The results suggest that anticoagulation does not p reclude the glomerular sieving of macromolecules, but seems to reduce tubular obstruction, probably by preventing conversion of filtered fib rinogen into fibrin.