Search Results

You are looking at 1 - 10 of 2,484 items for

  • Abstract: testicle x
  • Abstract: leydig x
  • Abstract: sertoli x
  • Abstract: epididymis x
  • Abstract: testes x
  • Abstract: seminiferous tubules x
  • Abstract: blood-testes barrier x
  • Abstract: interstitial x
  • Abstract: spermatogenesis x
  • Abstract: rete testis x
  • Abstract: cryptorchidism x
Clear All Modify Search
Free access

A. K. CHOWDHURY and E. STEINBERGER

Summary.

The influence of a cryptorchid milieu on the initiation of spermatogenesis was studied, utilizing the technique of transplantation of newborn rat testes into cryptorchid testes of adult hosts. The histological changes in the host and the transplanted testes were evaluated at various periods after transplantation. The transplant showed progressive growth and differentiation of the germ cells up to mid-pachytene stage within 30 days of transplantation into the cryptorchid testes. Thereafter, further progression of spermatogenesis did not occur and the germ cells gradually degenerated. Within 60 days, the seminiferous tubules in the transplant were lined by a layer of Sertoli cells and were comparable in appearance to the host tissue. In another group of animals where the cryptorchid testis was returned to the scrotum at the time of transplantation, both initiation and completion of spermatogenesis were observed. The results indicate that a cryptorchid milieu does not interfere with the initiation of spermatogenesis, but prevents its progression and maintenance.

Free access

R. M. LIPTRAP and J. I. RAESIDE

Summary.

Urinary excretion of dehydroepiandrosterone (DHA) and oestrogens was determined in five bilaterally cryptorchid boars and four unilaterally cryptorchid boars. Similar determinations were carried out in two boars made cryptorchid through surgery. The DHA and oestrogen values for the cryptorchid animals were comparable to normal boars of a similar age. These results suggest that the cryptorchid testes of the boar are capable of producing normal amounts of testicular steroid hormones.

Free access

Jane N. Scott, H. Ira Fritz and F. Nagy

Summary. Adult male opossums, Didelphis virginiana, were rendered hemicryptorchid for 35 days. The cryptorchid testis exhibited a significant reduction in weight, while the contralateral testis had a compensatory weight gain compared with testes of untreated animals. Histological changes in the cryptorchid testis included fibrosis of the tunica propria, involution of the seminiferous tubules and an apparent increase in the interstitial tissue. Many seminiferous tubules were empty and germinal cells were absent. Some Sertoli cells persisted, but the cytoplasm was vacuolated. Cryptorchid testes were characterized by mononuclear leucocytic invasion around the tubules, and some eosinophils were observed. Cryptorchidism in the opossum may induce a reaction similar to experimental orchitis.

Free access

Brian P. Setchell

The evidence for the lower temperature of the testes of many mammals is summarized, and the reasons suggested for the descent of the testes into a scrotum are discussed. Descriptions are given of the various techniques used for studying the effects of heat on the testis, whole body heating, local heating of the testes (by inducing cryptorchidism, scrotal insulation or immersion of the scrotum in a water bath), and heating of tissue or cell preparations in vitro. The effects of heat are discussed, effects on the testis (weight, histology, physiology, biochemistry and endocrinology), on the numbers and motility of spermatozoa in rete testis fluid and semen, on fertilizing ability of spermatozoa and on the subsequent development of the embryos produced when spermatozoa from heated testes are used to fertilize normal ova. The possible mechanisms for the damaging effects of heat are discussed, as well as the importance of heat-induced abnormalities in male reproduction in domestic animals and humans.

Free access

B. P. SETCHELL

Summary.

Fluid secretion by the seminiferous tubules of the testes of rats, rams and goats has been calculated from measurements of weight and water content of the testes after ligation of the efferent ducts. Measurement of fluid secretion made in this way gave similar results to other studies where the volume of fluid flowing from a catheter in the rete testis was measured. Fluid secretion was absent in the testes of very young animals but had reached adult proportions before the first spermatozoa were shed. Surgically-induced cryptorchidism and hypophysectomy in rats had no immediate effect on fluid secretion. Hypophysectomy in rats 1 to 4 weeks before efferent duct ligation caused a reduction in fluid secretion, but this fluid secretion was the same as that by control testes of the same weight. Cryptorchidism of 2 to 7 days' duration led to a decrease in fluid secretion. The ionic composition of fluid secreted by the testis was calculated and found to be similar to that of fluid collected from a catheter.

Free access

T. Jahnsen, B. Karpe, H. Attramadal, M. Ritzén and V. Hansson

Summary. Cryptorchidism was associated with increased responsiveness of the isoproterenol-sensitive adenylate cyclase in membrane particles from rat testis. Abdominal testes from uni- and bilaterally cryptorchid rats showed the same activities. The change in isoproterenol-responsive adenylate cyclase was independent of the age at which the animals were made cryptorchid. The isoproterenol response was maximal 3–4 weeks after the rats were made cryptorchid. By 2–3 months after orchidopexy the isoproterenol response in the rat testis had decreased to normal control values.

Free access

N. Leader-Williams

Summary. In a sample of reindeer from South Georgia, 4 males were abnormal in that 1 had bilateral cryptorchid testes, 2 each had 1 cryptorchid testis and 1 had a vestigial testis. The antlers of the cryptorchid males were small, but the antler cycle itself was hardly affected.

Free access

G. P. Risbridger, A. E. Drummond, J. B. Kerr and D. M. de Kretser

Summary. There was a significant (P < 0·05) and consistent increase in the potency of steroidogenic stimulatory activity (testosterone production by purified Leydig cells in vitro) in testicular interstitial fluid of the cryptorchid compared to the scrotal testis from 1 to 4 weeks after the induction of unilateral cryptorchidism. In contrast, the level of mitogenic activity ([3H]thymidine incorporation into 3T3 cells) was not significantly different between interstitial fluid from cryptorchid and scrotal testes for up to 4 weeks after surgery. These results indicate that the steroidogenic activity and the mitogenic activity are due to different, as yet unidentified, factors in testicular interstitial fluid.

Free access

B. Jégou, A. O. Laws and D. M. de Kretser

Summary. Cryptorchidism for 28 or 10 days resulted in a severe disruption of spermatogenesis (assessed histologically or by fertility tests), Sertoli cell function (assessed by seminiferous tubule fluid production after efferent duct ligation, ABP levels, binding of 125I-labelled FSH to testis homogenates and serum FSH levels) and Leydig cell function (assessed by serum LH and testosterone levels, in-vitro testosterone production, binding of 125I-labelled hCG). Orchidopexy after 28 days of cryptorchidism resulted in a poor recovery of spermatogenesis since the majority of tubules were lined by Sertoli cells and a few spermatogonia. No recovery occurred in the indicators of Sertoli and Leydig cell function.

Orchidopexy after 10 days of cryptorchidism also resulted in a poor recovery of spermatogenesis, with a few animals showing partial recovery after 6 months. No recovery occurred in seminiferous tubule fluid production but partial recovery occurred in ABP content and production rate. Serum FSH, LH levels and in-vitro testosterone production by the testis remained elevated and did not change from the values found during cryptorchidism.

Fertility testing at 6 months revealed a small number of rats in which fertility was restored although the number of embryos was lower than in controls. In this group of animals there was a significant improvement in a number of indicators of Sertoli cell and Leydig cell function. These data provide further evidence to link the changes in Sertoli cell and Leydig cell function to the germ cell complement present in the testis.

Free access

Y. Tajima, K. Sakamaki, D. Watanabe, U. Koshimizu, T. Matsuzawa and Y. Nishimune

Summary. The effects of Steel–Dickie (Sld) mutations on testicular germ cell differentiation were investigated using experimental cryptorchidism and its surgical reversal in mutant, C57BL/6-Sld/+ and wild-type C57BL/6- +/+ mice. In Sld/+ cryptorchid testes the maintenance of undifferentiated type-A spermatogonia was impaired and their numbers decreased. In contrast, the proliferative activity of type-A spermatogonia in the cryptorchid testis of mutant mice appeared normal as judged by their progression through the cell cycle. Surgical reversal of cryptorchidism resulted in regenerative differentiation of mature germ cells in +/+ testes. However, the regenerative differentiation of type-A spermatogonia which remained in Sld/+ cryptorchid testes was strongly impaired, particularly at two steps of cellular differentiation, from type-A spermatogonia to intermediate or type-B spermatogonia and at meiotic division. Furthermore, in mutant mice, no significant recovery of testicular weight was observed after surgical reversal compared with +/+ mice.

Keywords: Sld mutation; testis; germ cell; Sertoli cell; cryptorchidism; mouse