The effects of the agonal period and subsequent donor management on renal slice function, using the K+ – Na++ ratio, have been studied in the pig. Brain ischaemia or death resulted in a reduction in renal slice function, whether the pig was maintained normovolemic or bypovolemic by i.v. fluid and dobutaminc therapy. This deterioration in function was, however, reversed or prevented by a period of therapy with thyroxine (T3), insulin, and cortisol. A period of 24 hr storage of the kidney slice in a low ionic strength solution in ice resulted in a further deterioration in slice function in all groups studied. © 1986 by The Williams & Wilkins Co.