Morphological aspects of the rat kidney preserved by cold storage. IV. Histoenzymological changes. V. Endopeptidase...

Rat kidneys were preserved by initial washing and cooling perfusion, followed by cold storage at 6 degrees C for 24, 48, 72 and 96 hours, in two different media: Sacks (hyperosmolar electrolytic solution of intracellular type) and Plasmagel (gelation solution 4%). Evidence was found of DPNH-diaphorase, lactate dehydrogenase (LDH), leucylaminopeptidase (LAP) and adenosine-triphosphatase (ATPase) (pH 9.4) activities. Histoenzymological determination showed various levels of enzymatic activities in different segments of the nephron, levels relatively well maintained during storage, even at 72 and 96 hours. At the same time, cathepsin B and D and neutral proteinase activities were determined as parameters of maintained cellular enzymatic activity; different aspects were observed with the two preservation media used.