EPIDIDYMAL OBSTRUCTION DURING DEVELOPMENT RESULTS IN ANTISPERM AUTOANTIBODIES AT PUBERTY IN RATS

An autoimmune response to sperm occurs after vasectomy, but there is l ittle information on whether similar reactions occur after obstruction of the male reproductive tract at other points. Male Lewis rats recei ved bilateral ligation of the corpus epididymidis or a sham operation at age 10 days, and the subsequent systemic antisperm autoantibody res ponses were compared to those observed following obstruction of the va s deferens. After sexual maturation, rats with epididymal ligations ha d antisperm antibodies on an enzyme-linked immunosorbent assay that we re significantly higher than those of sham-operated animals and did no t differ from antibody levels in vasectomized rats at the same ages. W estern blot analysis showed that certain sperm proteins were recognize d by antisperm antibodies after both epididymal ligation and vasectomy , including the previously identified ''dominant'' autoantigens at 73- 83, 68-72, 48, 42, and 22 kDa. On the other hand, sera from rats with epididymal ligations recognized 60 and 52 kDa proteins that were not b ound by most postvasectomy sera. Conversely, 42-48 and 38-42 kDa bands were more strongly and frequently stained after vasectomy than after epididymal ligation. The results demonstrate that antisperm antibodies are produced after obstruction of the epididymis and that the magnitu de of the response is comparable to that after vasal obstruction. Diff erences in autoantigens recognized after epididymal and vasal obstruct ions may reflect maturational changes in sperm components that take pl ace during the passage of spermatozoa through the epididymis.