Disuse Atrophy of the Urinary Bladder After Bilateral Nephrectomy 1

Summary If both kidneys are removed from a rat which is kept alive by parabiosis to an intact partner, its unused bladder loses up to one-half the original weight. Such atrophic bladders persist indefinitely as organs composed mostly of dense fibrous connective tissue with attenuation of smooth muscle. In the intact partners, compensatory hypertrophy of both kidneys occurs, and the bladders become 50% larger than normal.