[Effect of Collins' solution the kidney concentrating gradient and the Na+ and K+-ATPase of the kidney].

Canine kidneys were preserved under hypothermia in Collins' standard solution and the contents of sodium, potassium, and Na+ and K+-ATPase in several parts of these kidneys were followed. Hypothermic preservation in combination with single perfusion by means of Collins' solution without thermic ischemia caused loss of sodium, increase of potassium, and decrease of the total osmotic cortico-papillary gradient of the kidney. No loss of Na+ and K+-ATPase activity occurred under these conditions. The determination of Na+ and K+-ATPase level in the renal tissue turns out to be a rational method to assess the vitality of an organ to be transplanted.