Fibrin deposition in the kidney in post-ischaemic renal damage.

To investigate whether fibrin deposition in the kidney occurs in ischaemic acute renal failure, rats were subjected to a left renal artery occlusion (RAO) for 1 h and contralateral nephrectomy. The animals were killed 0, 5, 15 and 60 min after re-establishment of the circulation. Kidney tissue was snap-frozen for immunofluorescence microscopy and scanning electron microscopy, and immersion-fixed for light microscopy and transmission electron microscopy. Immunofluorescence studies showed small amounts of immune reactive fibrinogen/fibrin deposits in the peritubular capillaries. Substantial amounts of fibrinogen/fibrin positive material was observed in Bowman's space and in the tubular lumina. Scanning electron microscopy of freeze-dried tissue disclosed granular and fibrillar material in Bowman's space. A temporary enlargement of Bowman's space was noted; it may have been caused by tubular obstruction. No deposits were found in the control (right) kidneys and in kidneys of heparinized rats subjected to RAO. The results indicate that fibrin deposition occurs in the ischaemic model of acute renal failure in rat, both intravascularly and in the urinary space. Its importance for the development of renal functional impairment remains to be studied.