The effect of cortisol on porcine articular tissues in organ culture.

(1) The effects of hydrocortisone succinate (1.0--0.01 micrograms HC/ml of medium) on porcine articular tissues in organ culture have been studied by histological and biochemical methods. (2) 1.0 and 0.1 micrograms HC/ml considerably inhibited the severe breakdown of matrix that occurs in living and dead cartilage explained in contact with synovial tissue. (3) The depletion of matrix in living cartilage cultivated in the same dish as but not in contact with synovial tissue, is much diminished when the medium contains 1.0 or 0.1 micrograms HC/ml. (4) Cartilage grown in the used medium of synovial tissue loses both proteoglycan and hydroxyproline; the addition of HC to the used medium has little (1.0 microgram HC/ml) or 0.1 microgram HC/ml) no inhibitory effect. If, however, the used medium is from synovial tissue that has been cultured in the presence of 1.0 or 0.1 micrograms HC/ml, loss of proteoglycan and collagen from the cartilage is much reduced. (5) In isolated cartilage in normal medium there is outgrowth of cells from the cut surface and some loss of proteoglycan and collagen; outgrowth is completely, and loss of matrix components partially suppressed by 1.0 micrograms HC/ml. (6) Isolated synovial tissue cultured in normal medium shrinks to about one-third of its original size, loses much of its collagen and secretes neutral metallo-proteinases into the medium; in the presence of 1.0 microgram HC/ml these changes are largely prevented. The explants also secrete an inhibitor of metallo-proteinases the production of which is not reduced by HC.