Degeneration of the seminiferous epithelium following epididymal obstruction in prepubertal rats.

The development of the testes was studied in rats following prepubertal obstruction of the epididymis. Male rats received bilateral ligation of the corpus epididymidis or a sham operation at 10 days of age, and temporal changes in testicular morphology and weights of reproductive organs were determined at intervals spanning sexual maturation. Development of the testes was normal through 35 days of age. The initial histological changes in the testes of ligated animals, observed at 56 days, included an increased diameter of the seminiferous tubule lumen, depletion of spermatids, and the presence of multinucleate spermatids. Subsequently, germ cells were greatly depleted in the testes of 91- and 128-day-old rats with ligated epididymides. After puberty, testicular weight and volume declined relative to corresponding sham-operated animals. On the other hand, the weights of the epididymides in ligated animals prior to puberty significantly exceeded those of sham-operated rats but weighed significantly less than those of rats in the sham group after sexual maturation. Testicular alterations occurred after increases in the weights of the epididymides. Testicular changes may have contributed to rather than resulted from an autoimmune response to spermatozoa because testicular alterations preceded increases in antisperm autoantibodies.

Epididymal obstruction during development results in antisperm autoantibodies at puberty in rats.

An autoimmune response to sperm occurs after vasectomy, but there is little information on whether similar reactions occur after obstruction of the male reproductive tract at other points. Male Lewis rats received bilateral ligation of the corpus epididymidis or a sham operation at age 10 days, and the subsequent systemic antisperm autoantibody responses were compared to those observed following obstruction of the vas deferens. After sexual maturation, rats with epididymal ligations had antisperm antibodies on an enzyme-linked immunosorbent assay that were significantly higher than those of sham-operated animals and did not differ from antibody levels in vasectomized rats at the same ages. Western blot analysis showed that certain sperm proteins were recognized 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 bound 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 magnitude of the response is comparable to that after vasal obstruction. Differences in autoantigens recognized after epididymal and vasal obstructions may reflect maturational changes in sperm components that take place during the passage of spermatozoa through the epididymis.

Appearance of 'natural' antisperm autoantibodies after sexual maturation of normal Lewis rats.

Serum antisperm antibodies were assessed quantitatively with an ELISA in normal male Lewis rats at intervals between ages 10 and 128 days, spanning the onset of puberty. Antisperm antibodies rose between 56 and 91 days, and were significantly higher in 91- and 128-day old rats than at earlier intervals. The animals underwent normal pubertal development as indicated by increases in weights of the seminal vesicles and ventral prostate. The rise in antisperm antibodies correlated temporally with events in the postnatal development of the male reproductive system, with the increase in antisperm antibodies most closely following the time when spermatozoa reach the epididymis and proximal vas deferens at approximately 56 days. The observation that serum antisperm antibodies increased only after sexual maturation suggests that some differentiation antigens of sperm are processed and presented to the immune system under normal circumstances in this strain. Western blot analysis showed that the sera from normal postpubertal Lewis rats bound several proteins, including bands of > 100, 82-75, 78, 68, 65, 63, 54-55, 42, 37, 35, 26, and 20-22 kDa. The majority of these autoantibodies were sperm-specific as shown by the absence of comigrating bands in western blots of somatic tissue extracts, although antibodies in postpubertal sera recognized certain other proteins in somatic tissues. Several protein autoantigens, defined by sera from postpubertal animals, matched dominant autoantigens recognized by antibodies produced in response to vasectomy, prepubertal vas obstruction, or immunization with spermatozoa. This finding indicates that the antisperm antibody responses following sperm immunization, vasectomy or prepubertal vasal obstruction represent accentuation of an autoantibody response to sperm that develops normally following puberty.

Sperm autoantigens recognized by autoantibodies in developing rats following prepubertal obstruction of the vas deferens.

Sperm protein autoantigens recognized by serum antisperm autoantibodies during development following vas deferens obstruction were studied using western blot analysis. At age 10 days, rats in an obstructed group underwent bilateral ligation and division of the vas deferens, whereas animals assigned to a sham group received a sham operation. At ages 14, 21, 35, 56, 91, and 128 days, rats were sacrificed and blood samples were obtained. Sperm antigens were recognized infrequently and with low intensity by most sera obtained at ages 14 through 56 days. Subsequently, the incidence as well as the intensity of staining of antigens in blots increased at 91- and 128-day intervals in obstructed animals. The increase in antisperm antibodies correlated with the appearance of sperm throughout the epididymis at approximately 56 days postnatally. A set of autoantigens including proteins migrating at 82-78, 76-73, 68, 57, 54, 48, 44, 42, 38-42, 36, and 22 kDa were recognized with the highest frequency and intensity after puberty. A 42-kDa protein appeared to be one of the first autoantigens recognized when obstructed animals underwent sexual maturation. Although individual animals recognized different patterns of sperm autoantigens, a repertoire of 10-12 autoantigens dominated the antisperm antibody response when obstructed animals underwent sexual maturation.

Testicular development and the formation of spermatic granulomas of the epididymis after obstruction of the vas deferens in immature rats.

PURPOSE: Aims were to determine the effects of obstruction of the vas deferens prior to sexual maturation on testicular growth and the formation of spermatic granulomas. MATERIALS AND METHODS: The vas deferens was ligated and divided bilaterally in 10-day-old Lewis rats. RESULTS: Testis weight and volume did not differ significantly between obstructed rats and sham controls at the majority of the intervals studied, including the end of the experiment at 128 days, although some temporary changes were observed. Testes of obstructed animals showed normal histological differentiation. Nearly all obstructed animals developed spermatic granulomas of the epididymis once they matured. CONCLUSIONS: When obstructed prior to sexual maturation, the testes are affected only transiently, but significant epididymal alterations occur. Spermatic granulomas are located predominantly in the epididymis rather than the vas deferens.

Temporal appearance of antisperm antibodies during sexual maturation of rats after obstruction of the vas deferens.

The appearance of serum antisperm antibodies was studied during the maturation of rats in which the vas deferens was obstructed prepubertally. Vasa deferentia were ligated and divided bilaterally in 10-day-old Lewis rats, while control animals received a sham operation at the same age. At ages between 14 and 128 days, blood samples were assayed for antisperm antibodies using an enzyme-linked immunosorbent assay. There were no differences between obstructed and sham-operated groups in mean antisperm antibodies from 14 through 56 days. However, in 91- and 128-day-old rats mean antisperm antibody levels were much higher in obstructed than in control animals. This rise in antisperm antibodies occurred several weeks after the development of spermatids in the testes between 23 and 46 days. The presence of elevated antisperm antibodies in obstructed animals followed temporally the appearance of sperm throughout the lumen of the entire epididymis and the formation of spermatic granulomas. The results in this model suggest that consideration be given to repair of injured or obstructed vas deferens prior to puberty to forestall development of antisperm antibodies, as well as the formation of spermatic granulomas.