Experimental Epididymitis Induced by Repeated Injection of Homologous and Heterologous Epididymal Tissue with Adjuvant

Joo, Suk Ki; Lee, Hak Song; Lee, Chae Koo

Abstract

A number of chronic inflammatory lesions of unknown etiology in man have recentlybeen understood by the mechanism of so called auto-immune disease and a series of experimental study using animals have been extensively undertaken to reproduce the lesion. Experimental chronic inflammatory diseases induced by repeated injection of homologous or heterologous tissue antigen with adjuvant are based upon immunological process and these are readily reproducible. The author has experimentally studied on any allergic destruction of the epididymis of the rat on immunologic process as in other particular organs and tissue. A total of 59 white healthy male rats were divided into 7 major experimental groups of injection as follows. Group 1: six rats, control, injection with normal saline alone. Group 2: six rats, injection with adjuvant only. Group 3: six rats. injection with epididymal tissue only. Group 4: twenty-three rate, injection with rat epididymal tissue plus adjuvant. A. seven rats, sacrificed on the 64th day B. ten rate, sacrificed on the 92nd day C. six rats, sacrificed on the 128thday Group 5. six rate, injection with rat epididymal tissue plus adjuvant plus prednisolone. Group 6: six rats, injection with rabbit epididymal tissue only Group 7: six rats, injection with rabbit epididymal tissue plus adjuvant Injections were given into the abdominal muscle of the rat once s week for 8 weeks as scheduled in the text and the animals of all groups except the group 4, were sacrificed 8 days after the final injection. In the group 4, animals were further divided into 3 subgroups which were sacrificed on the 61st, 92nd and l28th day of the experiment, respectively. The epididymis and other organs of allexperimental animals were studied histopathologically and the following results were obtained; 1. In all rats of the group 1 receiving homologous epididymal tissue with adjuvant, the epididymis revealed relatively marked and significant inflammatory changes. Histopathology included edema, congestion, fibrosis in the interstitial tissue, and infiltration of inflammatory cells mainly composed of lymphocytes, histiocytes, plasma cells and eosinophils. Flattening and hyperplasia of the epithelial cells and cellular exsudation were observed in the tubules. 2. In the group 1, the lapse of time after injection provoked more marked inflammatory changes. Diffusely mild or moderate degree of inflammation observed on 61st day, was changed to diffusely moderate or marked inflammation on 92nd day and then to significantly more chronic lesion with less exsudation and more fibrosis on 128th day. 3. Homologous tissue antigen without adjuvant andheterologous tissue antigen with or without adjuvant caused no inflammatory changes. 4. Inflammatory changes induced by homologous tissue antigen with adjuvant seem to be readily inhibited or prevented by simultaneous administration of prednisolone.