Cell recruitment to the sperm granuloma which follows vasectomy in the rat

Epididymal Sperm Granuloma and Antisperm Antibodies in Donkeys

This study aimed to describe and compare semen parameters (pre-freeze and post-freezing) and antisperm antibodies (ASA) of donkeys with epididymal sperm granuloma and healthy controls. Feral donkeys (n = 10) castrated in a concurrent study were enrolled in the present experiment. Three donkeys had unilateral granulomas, two donkeys had bilateral granulomas, whereas the remaining five had grossly normal epididymides. The granulomas were either single or multiple, firm, well-circumscribed, tan to red, and 1-5 mm in size. Upon incision, abundant, thick, tan to white-yellow fluid was recovered. Histopathology revealed epithelioid macrophages, multinucleated giant cells, and abundant sperm cell fragments with mineralized cellular debris. Each epididymis was dissected, and semen harvested for cryopreservation. Semen was assessed for sperm motility parameters, plasma membrane integrity, and mitochondrial membrane potential. All donkeys had semen cryopreserved in a standard manner. In addition, post-thaw semen from all donkeys was assessed for ASA (IgG and IgA), acrosome integrity and morphology. Post-thaw, the progressive sperm motility and the percentage of sperm with an intact plasma membrane were reduced in donkeys with sperm granuloma (P = 0.04). There was no difference in total sperm motility, morphology, or damaged acrosome across groups (P > 0.05). Three donkeys with sperm granuloma (60%) displayed increased IgG and IgA ASA. In conclusion, sperm granulomas only marginally affected sperm quality and resulted in IgG ASA binding to sperm with damaged plasma membrane. It remains to be determined if sperm granuloma and ASA affect fertility in donkeys.

Clinical and Pathological Findings in Testis, Epididymis, Deferens Duct and Prostate following Vasectomy in a Dog

We report the case of a bilateral and multilocular spermatocele and sperm granuloma in a dog that was vasectomized 5 years before. Clinical examination revealed scrotal dermatitis and benign prostatic hyperplasia. Orchiectomy was performed, and gross and histological examination showed testicular degeneration associated with epididymal sperm granuloma. In relation to this case, the literature about long-term effects of vasectomy in dogs has been reviewed. On the basis of these results, a preventive sonogram and physical assessment in prostate and other reproductive structures before vasectomy is recommended.

Vasectomy reversal and spermatic granuloma: experimental investigation

The aim of our study was to investigate the healing process after vasectomy reversal, comparing two suturing techniques. Eighty Wistar rats received a two-layer vaso-vasostomy on the right side, and 40 of them also received a single-layer vaso-vasostomy on the left side. Twenty rats each time were sacrificed at 30, 45, 60, and 90 days. Results were evaluated in order to compare the two techniques used and to describe the progression of healing, with special reference to anastomotic patency rate, histologic aspect of the epididymus and testicle, and the presence and size of spermatic granuloma. We observed 45% patency with the double-layer technique compared to 20% with the single-layer technique. The testicle appeared atrophic in 20% of double-layer cases compared to 40% of single-layer cases. Comparison over time showed a progressive increase in patency of the anastomosis, reduction of spermatic granuloma, and regression of testicular damage. Our results show the superiority of the double-layer technique, and contribute to an understanding of the role of two different suturing techniques in the outcome of vasectomy reversal.

Macrophage Populations in l-Cysteine-Induced Rat Sperm Granulomas

Histopathologically, sperm granulomas consist of a central mass of degenerating spermatozoa surrounded by many epithelioid macrophages and lymphocytes. Using monoclonal antibodies (ED1, ED2, and OX6), the authors investigated immunohistochemically the participation of different macrophage populations in epididymal sperm granulomas induced in pubertal rats by repeated injection of L-cysteine. Monocyte-like and epithelioid macrophages expressed the ED1 antigen found on activated lysosomal membranes in rat blood monocytes and exudate macrophages, but did not express the ED2 antigen found on the membrane antigens of rat resident macrophages. Cells expressing MHC class II antigens (as detected by the OX6 antibody) were present in the granulomas in moderate numbers, particularly in the early stages. Ultrastructurally, fragmented spermatozoa were observed in the cytoplasm of epithelioid macrophages. These findings suggest that macrophages appearing in rat sperm granulomas originate mainly from blood monocytes, and that they have a high phagocytic activity and a potential for antigen presentation.

Relationship of interstitial edema with L-cysteine-induced sperm granulomas in the pubertal rat epididymis

Although the pathogenesis of sperm granulomas is complicated, the leakage of spermatozoa into extraluminal tissues is regarded as a crucial event. It has been previously shown that pubertal rats injected with L-cysteine develop interstitial edema followed by sperm granulomas in the epididymis. In this study we investigated the relationships between these two lesions in 6-week old rats given daily intraperitoneal injections of L-cysteine (1,000 mg/kg body weight) for 4 weeks. Rats were examined during weeks 0, 1, 2, 3 and 4 after the first injection. Interstitial edema (moderate or severe) and sperm granulomas were seen in the corpus and cauda epididymis of L-cysteine-treated rats in study weeks 2, 3, and 4. There was no marked alteration of basement membrane of the epididymal ducts in the edematous tissues as shown by immunohistochemistry with an antilaminin antibody. However, the extravasation of Evans blue dye given I hour before necropsy suggested that the severe interstitial edema was due to increased vascular permeability. In addition, a small number of neutrophils were seen in the edematous tissues, suggesting that they might play a role in the increased vascular permeability and leakage of epididymal fluid. Interestingly, slight interstitial edema was observed in the caput epididymis in both control and L-cysteine-treated rats in early study weeks 0, 1, and 2. It is speculated that this change was related to the leakage of epididymal fluid due to increased intraluminal pressure depending on rat epididymal maturation. Taken together, these findings suggest that the severe interstitial edema results from increased vascular permeability. This, along with increased intraluminal pressure, might be the trigger for duct rupture, the prerequisite for sperm granuloma formation associated with excessive doses of L-cysteine.

Self-expandable chitosan stent: design and preparation

Stents are largely used in surgical procedures to relieve pathological obstructions. The purpose of the present study was to design and prepare a biocompatible stent with a self-expandable mechanism. Thin films were prepared from deacetylated chitosan (4% w/v) dissolved in acetic acid solution (2% v/v). The chitosan films were tested by a calibrated tensiometer to measure the Young's module (E). The films were used to manufacture stents by pulling and winding them around a cylindrical rod in a helical fashion. Thirteen stents (diameter = 0.5 +/- 0.05 mm, length approximately 4 mm) were inserted into the vas deferens of wistar rats. Upon stent insertion, the vasal anastomosis was achieved with a laser-soldering technique. The animals were sacrificied 8 weeks later. The stress test showed that the chitosan film was elastic (maximum strain = 105% +/- 6%, E = 0.7655 +/- 0.0288 Mpa). The stents self-expanded by releasing their elastic energy. All the stents but one remained open inside the vasa despite high incidence of sperm granuloma. A biocompatible and self-expandable stent with a helical design is proposed.

Cellular responses to vasectomy

A number of cell populations in the reproductive tract show a response to vasectomy. Some cell types show similar responses in man and all laboratory species, whereas others show marked species variations. This chapter describes these effects in a broadly chronological order and, in a general way, considers changes close to the site of vasectomy first and the longer term effects on the testis itself later. Following vasectomy, epididymal distension and sperm granuloma formation result from raised intraluminal pressure. The sperm granuloma is a dynamic structure and a site of much spermatozoal phagocytosis by its macrophage population. In many species, spermatozoa in the obstructed ducts are destroyed by intraluminal macrophages, and degradation products, rather than whole sperm, are absorbed by the epididymal epithelium. Humoral immunity against spermatozoal antigens following vasectomy is well established and there is evidence of modest T-lymphocyte activity. The role of lymphocytes in the reproductive tract epithelium and interstitium following vasectomy is poorly defined. In laboratory animals, there is evidence that pressure-mediated damage to the seminiferous epithelium can follow sperm granuloma formation and obstruction in the epididymal head. However, the contribution of lymphocytes and antisperm antibodies to testicular damage after vasectomy is far from clear. A number of studies have suggested that testicular changes may follow vasectomy in man but their validity and mechanism of occurrence require further study.

Macrophages of the sperm granuloma 3 months after vasectomy in the Albino Swiss rat

This study documents the appearance and arrangement of the macrophages of the sperm granuloma 3 months after vasectomy in the Albino Swiss rat. We found, as have others, that the macrophages form a distinct layer in the granuloma wall, external to the central mass of extravasated spermatozoa. Those closest to the spermatozoa showed much phagocytosis. Many had two, three, or more nuclei. The largest macrophages, giant cells of the foreign body and Langhans types, were generally farther from the sperm mass, but retained evidence of phagocytic activity in the form of sperm fragments. Macrophages, either mono- or multinucleate, frequently showed numerous surface microridges that interdigitated with those of neighboring cells. The microridges varied in length, but were of uniform thickness and cytoplasmic content and were rarely branched. Monocytes were frequently observed, indicating continuing significant recruitment of cells of the macrophage series to the granuloma. We also noted mononucleate cells in the connective tissue external to the macrophage layer. Their cytology suggested they were macrophages, but they showed much less phagocytic activity than those of the main macrophage layer and had distinctive aggregations of moderately electron-dense droplets.

Observations on multiple sperm granulomas in the rat epididymis following vasectomy

Seven epididymides of long-term vasectomized rats showing multiple sperm granulomas were studied in serial histological sections. Despite the presence of the multiple granulomas, only two rats showed continuity of the epididymal duct with the central sperm mass of a granuloma. A further three specimens showed breaks in the epididymal epithelium at sites of local distension in the epididymal tail. Granulomas in the epididymal body seem to receive spermatozoa only transiently. The spermatozoa at the center of granulomas in continuity with the epididymal duct showed evenly distributed sperm heads. A number of others showed clumping of spermatozoa, attributed to stagnation of flow and fluid resorption. In many granulomas, folds in the macrophage layer with a connective tissue core rich in lymphocytes and plasma cells projected into the central sperm mass. We conclude that the sperm granuloma is a dynamic structure that shows changes with age and that the sperm granuloma closest to the testis must not be assumed to be the one that is draining the spermatozoa.

Predictive testing for pathogenic autoimmunity: the morphological approach

The term autoimmunity refers to physiologically normal immune processes against self-antigens. In rare cases, the regulatory mechanisms become deflective and the uncontrolled production of autoantibodies or activation of autoreactive T-cells can subsequently cause disease. Substances may be capable of evoking autoimmune disease, and it is a challenge in routine toxicology to recognize such substances. In in vivo toxicity studies, uncommon inflammation in exposed animals should be discussed in terms of non-immune toxicity (e.g. irritation), infection, allergy and autoimmunity, taking into account that a response in even a few animals may be significant. Moreover, early morphological indicators of inflammation and lymphoid organ alterations can direct further investigation.

Effect of long-term vasectomy on seminiferous tubules in the guinea pig

The little previous work on the influence of vasectomy on the guinea pig testis has given controversial results. One group reports that the guinea pig suffers autoimmune orchitis while others claim damage may be mechanical. To clarify the issue, this study compares the morphology of seminiferous tubules 3 years after left unilateral vasectomy (8 guinea pigs) and control sham operation (6 animals). Grossly, left and right testes following left-sided vasectomy were similar to controls and not significantly different in weight. On histology, left and right experimental testes and the control material showed various degrees of seminiferous tubular degeneration, including intraepithelial vesicle formation, loss of germ cells and intraluminal macrophages. Although vesicle formation was striking in most testes, quantitative analysis indicated that it was more frequent in the ipsilateral testis following unilateral vasectomy. It seems that vasectomy had exacerbated an age-related phenomenon. Lymphocytic infiltration was seen in five of the left testes following vasectomy, in two of the corresponding right testes, but in none of the controls. Two vasectomized left testes, however, showed atrophic changes but no lymphocytic invasion. The results suggest that autoimmune orchitis follows vasectomy but that it may not be the primary cause of degeneration. Attempts to gain positive evidence for mechanical damage, however, were inconclusive.

Vasectomy review: sequelae in the human epididymis and ductus deferens

Following vasectomy, spermatogenesis continues, the human epididymis and ductus deferens may distend and leak, and the extravasated spermatozoa stimulate formation of a sperm granuloma. Granulomas may occur at 60% of vasectomy sites and are usually asymptomatic and relieve intraluminal pressure. About 3-5% of patients experience pain. Intraluminal phagocytosis may explain why some reproductive tracts become depleted of spermatozoa. Distension of the epididymis is common after vasectomy and may lead to granuloma formation there. Up to 6% of patients have symptoms, but many with epididymal changes have no discomfort. Most episodes of painful epididymitis and granulomas resolve with conservative treatment, but < 1% require vasectomy reversal or, if this is ineffective, excision of the epididymis and obstructed ductus deferens.