Pathological Changes in the Dog Kidney Resembling Normal Histological Structure in the Aglomerular Fish Kidney, Opsanus Tau.

Abstract

During the past 10 years investigations, , have been in progress in this laboratory which have been concerned with the acute changes of a degenerative character which may be induced in the dog kidney by the use of suitable subcutaneous injections of uranium nitrate, and with the histological changes arising as processes of repair in the kidneys of animals which survive such injections that result in the development of a pathological state which may be designated a chronic nephritis. This preliminary report is based on the study of the kidneys of 6 dogs with a chronic nephritis developing from the use of uranium, the duration of which has varied from 4 years to 6 years and 8 months. In addition to the usual routine functional studies which have been made of the blood and urine of these animals, histological studies have been undertaken of biopsy material removed from the kidneys before the commencement of the uranium intoxications, during the acute degenerative phase of the renal injury and at intervals of 3 months during the periods of repair which have resulted in the establishment of a chronic nephritis. The biopsy material obtained for study has been in the form of wedge shaped pieces of tissue taken from both poles and the outer convex border of the kidneys. Such material has represented a cortical surface 1-1.5 cm. in width with a depth extending into the substance of the kidney of 0.5-1.5 cm. The exposed renal surfaces caused by the removal of such material were closed with cat gut chromicised sutures. The tissue was fixed in corrosive-acetic, cut in serial sections and stained with haematoxylin and eosin. The primary injury to the kidney from uranium, as has been emphasized by Suzuki, is to the convoluted tubule epithelium. The processes of degeneration and repair to this tissue have been described., The glomerular injury which is delayed in its development, results during a period of years in inducing either a partial or complete structural obliteration of these structures so that areas exist in the kidneys of such animals, as shown in serial sections, in which the glomeruli are either destroyed by a process of connective tissue formation with a secondary hyalinization or they exist as relatively avascular units in which one or more capillary loops remain open for blood distribution.