Metallothionein in rabbit kidneys preserved for transplantation

Thirteen rabbits were given repeated cadmium injections to achieve cadmium concentrations in kidney cortex ranging from 0.05 to 1 mmole Cd/kg wet weight. Another four animals served as controls. One kidney from each animal was frozen directly to -70 degrees C whereas the other kidney was kept for 24 hr at +4 degrees C in a preservative (Sachs' solution) to simulate conditions for preservation of human donor kidneys before transplantation. Protein binding of cadmium, zinc and copper in kidney homogenates and the concentration of metallothionein (MT) were measured in the kidney that was frozen directly and in the kidney that had been preserved. No gross differences in either the protein binding of cadmium, zinc and copper or in the MT content were seen between the directly frozen and preserved kidneys from the same animal. This indicates that MT is not rapidly broken down in rabbit kidneys which have been preserved similarly to human donor kidneys for 24 hr in a standard preservative solution prior to a transplantation.