Effects of aprotinin on organ cultures of the rat's kidney.

Fragments of adult renal tissue were maintained as organ cultures for 7 days in HEPES-buffered medium 199, supplemented with 10% calf serum and antibiotics. Addition of aprotinin (10,000 kallikrein inhibitor units per ml) to the medium resulted in improved survival of the cells of the glomeruli and tubules and preserved the integrity of the glomerular, capsular and tubular basement membranes. Optimal results were obtained when aprotinin was present throughout the period of culturing. Inclusion of aprotinin in the medium for only the first 3 days in vitro slightly increased the numbers of surviving glomerular and tubular cells, but also promoted the growth of connective tissue in the explants and was detrimental to the basement membranes of the tubules. It is suggested that both the antiproteolytic and the carbohydrate-binding properties of aprotinin are involved in the mediation of the observed effects.