Experimental Cystic Disease of the Kidney Morphometric and Ultrastructural Studies in Special Reference to its Histogenesis

Yoo, Jong Keun; Kim, Young Kyoon

Abstract

Cystic lesions of the kidney were experimentally induced by a single injection of methylprednisolone acetate(MPA), 20mg/kg, and morphometric analysis and ultrastructural observations by means of trans. mission and scanning electron microscopes were carried out after 1,2,3 and 4 weeks to clarify the nature of the cysts and their Histogenesis. l. The cystic lesions developed by administration of MPA were categorized into tubular and glomerular cysts ; the former underwent gradual regression of its number after the first week together with reduction of its ratio to the renal volume, whereas the latter progressed. 2. The subcapsular cystic structures(average diameter of ll0um) was originated from the dilated collecting tubules by 180 degree rotation in regard with abnormality in maturation process of nephorgenic activity. 3. Abnormalities of both proximal and distal convoluted tubules were reflected by increases of tubular diameter(l.54~3.55 times) and nuclear density(1.77~l.72 times), representing a compensatory dilatation of tubular lumen in association with shortening of tubular length. 4.Convolution of tubules was reduced and parallel to the shortening of tubular length. The above morphometric and ultrastructural features support that cystic lesion in the subcapsular portion induced by administration of MPA arises from the subcapsular collecting tubules by maturation arrest of nephorgenic activity.