Apoptosis as a prognostic marker in prediction of renal injury, after acute bleeding and volume replacement with HES 130/0.4 or Ringer solution, in a pig model

Objectives: The aim of this study is to identify and quantify apoptosis in renal tissue, using a biochemical marker (TUNEL) in a pig haemorrhagic model, after intravascular volume replacement with Ringer's lactate RL) or Hydroxyethylstarch (HES) 130/0.4) solutions. Methods: 18 Large White pigs underwent total intravenous anaesthesia (TIVA) with propofol and remifentanil. 25 ml/kg of arterial blood were removed from the femoral artery. Volume was replaced, RL, in group1 (n=6) and HES 130/0.4, in group2 (n=6), 20 min after bleeding. The control group did not face bleeding and volume reposition. One hour after volume replacement, pigs were euthanized with intravenous KCl, and renal tissue samples were taken for several studies, including immunohistochemically with in situ TUNEL method for apoptosis detection. ANOVA was used to compare data between groups. Results: In all groups apoptosis was, as expected, mainly detected in epithelial tubular cells of the proximal and distal convoluted tubules, in the loop of Henle and in the epithelium of collecting tubules, however the number of apoptotic cells per mm2 was lower in group 1 (35.68 apoptotic cells/mm2), when compared with group 2 (67.94 apoptotic cells/mm2) and the control group (146.34 apoptotic cells/mm2). The level of apoptosis was significantly higher in Ringer Lactate group, comparing with controls group, for the epithelial tubular cells (P<0.05). Conclusion: The median apoptotic levels were significantly lower in pigs, subjected to fluid replacement with RL, when compared with HES 130/0.4. Ringer lactate might promote better renal perfusion in the presence of severe hypovolaemia following acute haemorrhage.

FEDER funds trough the COMPETE Program, and by national funds from Portuguese Foundation for Science and Technology, under the project COMPETE: FCOMP-01-0124-FEDER-009525