Spermatogenesis in the rabbit following ligation of the epididymidis at different levels

Abstract

Ligatures were placed unilaterally on the ductus deferens (experiment l ) , on the ductus deferens and the middle of the corpus epididymidis (experiment 2) and on the ductus deferens, corpus epididymidis and ductuli efferentes (experiment 3) in 39 r,abbits. The untreated contralateral side served as a control. Vasectomy alone appeared to have no effect upon the testes, or upon spermatozoa accumulated during a period of 12 weeks proximal to the ligature. In experiment 2 severe disruption of spermatogenesis occurred. Diameter of the seminiferous tubules decreased, testes atrophied, and the stages of the seminiferous epithelium were abnormal and often not classifiable. Some regeneration was observed after 12 weeks.In experiment 3 therls was only a moderate and more transient disturbance of spermatogenesis. This occurred in spite of an accumulation of fluid in the testis due to the ligature on the Iductuli efferentes, which prevented testicular effluent from reaching the caput epididymidis. These results suggest that when testicular effluent is allowed to reach the caput, but nonresorbed residues are prevented from further transport (experiment 2), a feedback to the testis occurs which is more harmful than that produced by preventing tubular contents from leaving the testes.Although early literature is conflicting (see Poynter, '39 for refere:nces), uncomplicated vasectomy does not appear to result in testicular atrophy (Moore and Quick, '24; Young, '33; Poynter, '39; Amann, '62). However, when the epididymal lumen closer to the testes, or the ductuli efferentes are occluded by ligation, testicular damage occurs (VVagenseil, '28; White, '33; Young, '33; Harrison, '53; Baillie, '62; Glover, '62; Barack, '68; Igboeli and Foote, '68). These investigators found that there was an initial dilation of the seminiferous tubules associated with fluid accumulation, followed by varying degrees of degeneration. The testis m.ay increase in size and then atrophy. Only one report, utilizing the mouse, was found in which the effects of different levels of epididymal obstruction on testicular histology was examined quantitatively (Baillie, '62). Preliminary observations in rabbits on the frequency of seminiferous tubules in stage 8 following ligation was reported by Igboeli and Foote ('68). The latter report suggested that ligations at certain levels in the rabbit evoked considerably more trauma than in the mouse.The purpose of this study was to examine systematically and (quantitatively ANAT. REC., 164: 339-348. effects on the rabbit testis induced by obstructing the excurrent ducts at different levels. Post-operative periods were varied in length so that immediate and longerterm effects could be evaluated. MATERIALS AND METHODSThree experiments were conducted utilizing 30 mature Dutch-belted and nine New Zealand males. Ligations always were done unilaterally so that the contralateral testis could serve as a control. The side to be treated surgically was randomly assigned. The locations of the ligatures were as follows: (1 ) ...

Degeneration of the seminiferous epithelium following epididymal obstruction in prepubertal rats

“…Similarly, adult Wistar rats that had received an epididymectomy showed varying degrees of testicular changes which progressed to extreme degeneration of the seminiferous epithelium (Soler et al, 1990). Likewise, extensive damage to the seminiferous epithelium was observed in dogs after ligation of the cauda epididymidis (Vare and Bansal, 1974), although epididymal ligation was reported to result in temporary testicular changes followed by evidence of recovery in the rabbit (Paufler and Foote, 1969) and mouse (Baillie, 1962). As might be expected, the more proximal the site of epididymal obstruction, the greater the likelihood of testicular changes in rats (Macmillan, 1953;Harrison and Macmillan, 1954) and mice (Baillie, 1962).…”

“…Effects on the testis of epididymal obstruction in adults (usually unilateral) have varied, with some authors reporting substantial testicular damage (Harrison and Macmillan, 1954;Vare and Bansal, 1974), while others have observed that deleterious changes are followed by recovery (Baillie, 1962;Paufler and Foote, 1969). Among the possible mechanisms of testicular damage after epididymal obstruction are increased pressure in the seminiferous tubules (Vare and Bansal, 1974;Paufler and Foote, 1969), accumulation of metabolites (Pilsworth et al, 1981), and absence of substances secreted by the epididymis (Paufler and Foote, 1969;Soler et al, 1990). However, since antisperm autoantibodies rise after epididymal obstruction (Flickinger et al, 1998), an autoimmune reaction may also cause testicular changes.…”

Effects of vasectomy on the blood-testis barrier of the hamster

“…Whether or not vasectomy significantly interferes with normal testicular function has been one of the important questions in the area. There are reports of testicular function being seriously altered after vasectomy (Sackler, Weltman, Pandhi & Schwartz, 1973;Alexander, 1973; Kothari & Mishra, 1973), but there is evidence from a variety of primate and non-primate species which supports the concept that, in general, spermatogenesis continues in vasectomized males (Skinner & Rowson, 1968;Paufler & Foote, 1969;Flickinger, 1972;Vare & Bansal, 1973;Howards, Jessee & Johnson, 1975). Even in vasectomized males with persistent spermatogenesis, however, there are often signs of some alteration or impairment of the spermatogenic process (MacMillan, Desjardins, Kirton & Hafs, 1968;Igboeli & Rakha, 1970;Alexander, 1973).…”

Sperm Retention and Resorption in Sexually Active Rabbits with Epididymal Ligatures

“…11). Disruption of spermatogenesis ( 15) prevented a resupply of sperm until effective renewal of spermatogenesis was noted at 12 weeks. Ligatures on the ductuli efferentes, in Expt.…”

“…Atrophy of the testes has been observed in males vasectomized for several years ( 15). Thus, reduced spermatogenesis also may account for some of the difference.…”