[Effects of osmotic agents for cold kidney preservation]

The beneficial effect of UW solution may result from its ability to prevent tissue edema during cold storage. This study was conducted to determine which impermeant was effective in this regard during cold storage of a rat kidney in solution. Functional and morphological studies were made on a rat isolated perfused kidney (IPK) following 24 hour-cold storage in various tested solutions. Right nephrectomy was performed in 95 male rats by the method of Nishitsutsuji-Uwo et al and the kidney was perfused and stored at 4 degrees C for 24 hours as follows: glucose (194 mM) as a control, mannitol, sucrose, raffinose (140 mM in each), lactobionate (100 mM), raff + lact, hydroxyethyl starch 20, 40 (5%) with electrolyte composition essentially the same as that of Euro-Collins or UW solution. Kidneys stored for 24 hrs at 4 degrees C were perfused by the IPK apparatus. The perfusate flow rate was adjusted to maintain the renal arterial perfusion pressure at 100 mmHg. Raff, raff + lact or UW solution showed significantly higher fractional reabsorption of sodium than the control with no change in renal hemodynamics. The release of LDH into the perfusate was significantly less in raffinose than the control. Raffinose may thus be considered to function effectively as an impermeant for cold kidney preservation and molecule size would appear more important than negative charge for rat kidney preservation.