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  • Abstract: testicle x
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RD Zhang, XH Wen, LS Kong, XZ Deng, B Peng, AP Huang, Y Wan and ZW Yang

The aim of this study was to examine the controversial effects of experimental unilateral cryptorchidism and subsequent orchiopexy on the number of germ cells and other morphometric characteristics of testicular and epididymal structures in adult rabbits. Unilateral cryptorchidism was induced in 11 mature male New Zealand white rabbits by returning one testis, together with the ipsilateral epididymis, to the abdominal cavity via a surgical procedure. After 3 months, testes and epididymides were removed from six animals (and from six age-matched control animals that did not undergo the surgery). Orchiopexy was performed on the five remaining animals and the testes and epididymides of these animals (and an additional six age-matched control animals) were removed 7 weeks later. A contemporary, unbiased and efficient stereological tool, the optical disector, was used to estimate the number of nuclei in the testis and epididymis using methacrylate-embedded sections of 25 micron in thickness. Cryptorchidism resulted in severe testicular atrophy and spermatogenic arrest: type A spermatogonia and Sertoli cells only were seen in the seminiferous epithelium, and the number of type A spermatogonia per testis was reduced by 84%. After orchiopexy, the testis remained atrophied and the number of type A spermatogonia returned to the near-normal range in four of five animals, but spermatogenesis was recovered only partially at the stage of early primary spermatocytes (one animal), late primary spermatocytes (two animals) or spermatids (one animal). In conclusion, cryptorchidism caused severe spermatogenic arrest that was potentially recoverable (in view of the restoration of the number of type A spermatogonia), but orchiopexy failed to induce full recovery of spermatogenesis.

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C. A. Grocock, H. M. Charlton and M. C. Pike

Summary. A single subcutaneous injection of 5 or 1 mg oestradiol given to pregnant female mice on Day 14 of pregnancy resulted in all male offspring being cryptorchid. Pituitary LH content, testicular weights and structure, seminal vesicle weights and the structure of the reproductive tract as a whole were monitored on the day of birth and at 2, 4, 8 and 14 weeks of age. Apart from an initial significant reduction in pituitary LH at the time of birth, no other marked differences were seen between control and treated animals except that all oestrogen-treated males lacked a gubernaculum and the testes were freely mobile within the abdomen. Hypogonadal (hpg) male mice lacking GnRH are cryptorchid but have a normal gubernaculum and their testes develop and descend normally if treated with gonadotrophins. When the mothers of hpg mice were treated with oestradiol the male offspring lacked a gubernaculum. These results indicate that perturbations of the fetal hypothalamic/pituitary axis play no significant part in oestrogen-induced cryptorchidism in mice.

Keywords: cryptorchidism; gubernaculum; maternal; oestrogen; LH; mouse

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B. Radhakrishnan and C. A. Suarez-Quian

Summary. The presence of the epidermal growth factor receptor (EGFR) in testis, epididymis and vas deferens of monkeys was demonstrated using a polyclonal antibody (RK2) raised against a peptide-specific sequence of the intracellular domain of the human EGFR. Immunoblotting of membrane preparations revealed a specific band at approximately 170 kDa corresponding to those of controls, A431 and monkey liver cells. Cryostat sections were stained by biotin–streptavidin peroxidase immunocytochemistry. The liver showed positive staining along the basolateral membranes of the hepatocytes lining the sinusoids. The testis showed positive staining indicating the presence of EGFR in Leydig cells, Sertoli cells and peritubular cells. In the epididymis, immunostaining of the EGFR was observed on both the basolateral and the luminal borders of the epididymal epithelium. Immunofluorescence studies revealed a similar pattern of EGFR distribution in the epididymis and indicated that the luminal immunostaining was vesicular. In the vas deferens, positive immunostaining was detected in a pattern very similar to that observed in the epididymis. There was no positive staining in the interstitium of the epididymis or in the smooth muscle cell layers of the vas deferens. The sections of all tissues treated with pre-immune serum were negative. These results suggest that EGF in the primate testis may act at the level of somatic cells. In addition, the basolateral and luminal EGFR staining in the epididymis and vas deferens suggest that these cells respond to an EGF, or EGF-like, source both at the basal, luminal or at both sides of the cells, or that these tissues serve as sites of EGF transcytosis across the epithelium.

Keywords: EGF receptors; spermatogenesis; immunocytochemistry; monkey; testis

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R. V. SHORT, J. L. HAMERTON, SUSAN A. GRIEVES and CAROLYN E. POLLARD

Summary.

Results are presented of a detailed anatomical, histological, steroid and cytogenetic study of a genetically female intersex goat with testes but with no ovarian tissue, and with a bilaterally asymmetrical reproductive tract anterior to the ampullae of the vas deferens. The gonads consisted of a well-developed testis on the right side and a smaller intra-abdominal gonad on the left. On the right side there was a well-developed epididymis and vas deferens and absence of development of the Müllerian duct. On the left side there was a well-developed and fluid-filled uterine horn, a vas deferens, but no epididymis. Both gonads showed the histological appearance of testes, although there was complete absence of spermatogenesis and the left gonad was necrotic.

Chromosome studies showed this animal to be a genetic female with 60 acrocentric chromosomes and no evidence for the presence of a Y chromosome (60, XX). Steroid concentrations in the right gonad were comparable to those in the testis of a normal male; in the left gonad, however, both testosterone and androstenedione were undetectable.

These results are discussed in relation to evidence that the testis is able to exert a local action on its adjacent genital ducts as well as a systemic action on the external genitalia.

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M. Fujisawa, O. Matsumoto, S. Kamidono, F. Hirose, K. Kojima and S. Yoshida

Summary. The activities of DNA polymerase α (EC 2.7.7.7) and topoisomerase I did not fluctuate up to 7 days after surgery to induce cryptorchidism and showed no significant difference from those in control testes (sham-operated). In contrast, the activity of DNA polymerase β decreased by 43% at 5 days (P < 0·01) and by 47% at 7 days (P < 0·001). The activity of DNA polymerase γ also decreased by 46% at 3 days (P < 0·02) and by 78% at 7 days (P < 0·01) after surgery. The amount of mRNA for DNA polymerase β decreased in parallel with enzyme activity. Since the sensitivity to heat inactivation of testicular DNA polymerase β was exactly the same as that from liver, the decrease in DNA polymerase β activity may be, at least in part, due to reduced biosynthesis of enzyme protein. The morphological changes in cryptorchid testes suggested that the decrease in DNA polymerase β and γ activities might be related to the deleterious effects of elevated temperature on spermatogenesis.

Keywords: DNA polymerase α, β, γ; topoisomerase I; rat; cryptorchid testes

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Elizabeth M. Edwards, J.-L. Dacheux and G. M. H. Waites

Summary. Spermatozoa were collected from the rete testis and vas deferens of conscious rams. The endogenous oxygen uptake of the spermatozoa was unaffected by α-chlorohydrin added in vitro, although this compound abolished the stimulation of oxygen uptake caused by the addition of glycerol. The metabolism of [14C]glycerol by testicular and epididymal spermatozoa was markedly reduced by α-chlorohydrin, CO2 production and lactate accumulation being almost totally inhibited. These effects were dependent upon a period of preincubation of the spermatozoa with α-chlorohydrin alone, since the presence of glycerol protected the spermatozoa from its action. Longer exposure and a higher concentration of α-chlorohydrin were needed with testicular than with epididymal spermatozoa to achieve a maximal effect. The metabolism of [14C]glucose by both sperm types was also inhibited by α-chlorohydrin. Spermatozoa of the ram are therefore susceptible to the action of α-chlorohydrin throughout the epididymis, although more mature spermatozoa are more affected. It is suggested that α-chlorohydrin is converted to an intermediate which is the agent responsible for the inhibition of glycolysis in spermatozoa.

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V Elfgen, A Mietens, M Mewe, T Hau and R Middendorff

During their transit through the epididymis, spermatozoa mature and acquire motility and fertilizing capacity. The smooth muscle cells (SMCs) of the epididymal duct are thought to be responsible for the adequate transport of spermatozoa. Thus, precise regulation of SMC function also represents a prerequisite for sperm maturation thereby contributing to male fertility. In this review, we would like to highlight various aspects of epididymal SMC function and discuss several angles with respect to regulation of contraction and relaxation. Different to the vas deferens, where disturbed SMC pathways resulting in male infertility could be defined, comparable information is missing in the epididymis. We therefore include some vas deferens data which could also be useful for a better understanding of epididymal SMC function. Furthermore, we would like to draw attention to drugs used in clinical practice and their potential (side) effects on contractions in the epididymis.

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K. Gerozissis and F. Dray

The biosynthesis of prostaglandins (PGs) occurs in the testes and seminal vesicles of various animal species (Carpenter, Manning & Wiseman, 1971; Christ & Van Dorp, 1972; Ellis, 1972). The effects of PGs on the contractility of the testicular capsule, epididymis and vas deferens in vitro and the effects of PG administration on the transport of spermatozoa suggest a possible role of PGs in the physiology of the male reproductive system (Davis, Langford & Kirby, 1970; Hafs, Louis & Stellflung, 1974).

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F. H. WILCOX

Summary.

Chemical analysis has revealed that the seminal plasma of the chicken contains high levels of acid phosphatase and low levels of alkaline phosphatase. There were significant differences in the acid phosphatase levels of individual males, but not of different breeds. Analysis of various sections of the male reproductive system demonstrated high levels of the acid phosphatase in the vas deferens and epididymis, and lesser but substantial amounts in the other sections tested.

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B. R. Williamson, B. A. Shepherd and J. Martan

Summary. Guinea-pigs were inseminated with spermatozoa from the vas deferens, where they are characteristically arranged in rouleaux, or from that part of the epididymis where rouleaux are infrequent. Fertility was much reduced in the 16 females inseminated with a suspension of single spermatozoa: only 4 became pregnant (compared with 10/11 controls) and all these had had some (0·5–0·75%) rouleaux in the insemination suspension. It is concluded that rouleau formation is indicative of physiological as well as morphological maturity.