Adrenal corticosteroid-induced renal cystic disease in the newborn hamster.

A new model of renal cystic disease was developed in newborn Syrian hamsters by the repeated injection of 9-fluoroprednisolone acetate (9-FPA), a long-acting adrenal corticosteroid. Kidneys harvested from the tenth to the fourteenth day of age showed diffuse cystic dilatation of nearly all cortical convoluted tubules. Microdissection revealed that cystic changes primarily involved proximal convoluted tubules and, to a lesser degree, the distal tubules. Electron microscopy showed immaturity of development and varying degrees of degeneration of the cells of the proximal convoluted tubule. Intraluminal obstruction was not detected and therefore could not account for the cystic changes. Analysis of electrolytes in serum and selected tissues showed a significant reduction in potassium and sodium of serum, and significant depletion of potassium, magnesium and calcium in the skeletal muscle. Thus, there was no direct relationship between an electrolyte deficiency and the cystic changes.