Damaging effect of subzero temperature (−4 °C) on rabbit renal function

The effect of exposing rabbit kidneys to −4 °C for 1 hr in the unfrozen state was evaluated by means of measurement of tissue slice K Na ratio and whole organ creatinine clearance. Freezing was prevented in one series (groups SC1–SC3) by supercooling with temperature monitoring and in a second series by a 2 M mixture of propylene glycol and glycerol. The latter agent was introduced prior to storage and later removed before the viability testing using a perfusion method (groups CPA1–CPA4). The results indicated a significant loss of slice and whole organ function during this short period of supercooling. The injury did not appear to result from either the rapidity of cooling or the formation of ice. There was some loss of function resulting from perfusion itself. Since this injury was evident in the whole organ but not in the tissue slice it may be ascribed to a vascular affect. When this damage was taken into account the data indicated that cryoprotective agents appeared to protect against any additional damage resulting from 1 hr storage at −4 °C.