Later onset of apoptosis in the bulbourethral glands after castration compared to that in the seminal vesicles

Phthalate esters affect maturation and function of primate testis tissue ectopically grafted in mice

Di-n-Butyl (DBP) and Di-(2-EthylHexyl) (DEHP) phthalates can leach from daily-use products resulting in environmental exposure. In male rodents, phthalate exposure results in reproductive effects. To evaluate effects on the immature primate testis, testis fragments from 6-month-old rhesus macaques were grafted subcutaneously to immune-deficient mice, which were exposed to 0, 10, or 500 mg/kg of DBP or DEHP for 14 weeks or 28 weeks (DBP only). DBP exposure reduced the expression of key steroidogenic genes, indicating that Leydig cell function was compromised. Exposure to 500 mg/kg impaired tubule formation and germ cell differentiation and reduced numbers of spermatogonia. Exposure to 10 mg/kg did not affect development, but reduced Sertoli cell number and resulted in increased expression of inhibin B. Exposure to DEHP for 14 week also affected steroidogenic genes expression. Therefore, long-term exposure to phthalate esters affected development and function of the primate testis in a time and dosage dependent manner.

Development of strips of ovine testes after xenografting under the skin of mice and co-transplantation of exogenous spermatogonia with grafts

Xenografting of testicular tissue is an attractive new strategy for studying postnatal development of spermatogenesis and to preserve male genetics in large mammals. Typically, small cubes of immature testis (1 mm(3)) are grafted under the dorsal skin of immune-deficient mice. We attempted to increase the total number of seminiferous tubules in each xenograft with spermatogenesis by grafting flat strips of testis (approximately 9 x 5 x 1 mm) from ram lambs in immune-deficient mice. The percentage of grafts that survived and percentage of seminiferous tubules that developed spermatogenesis were the same as those reported after xenografting small cubes of lamb testis. Partially purified sheep spermatogonia were labeled with the fluorescent dye carboxy fluorescein diacetate succinyl diester and transplanted into the seminiferous tubules of one of the donor testis just before engraftment. The temporary label in the donor cells was detected for 4 weeks after xenografting, suggesting that co-engraftment of spermatogonia with testicular tissue may be a way to rapidly determine the effect of a specific gene on spermatogenesis. Finally, Sertoli cell lesions in xenografts of lamb testes were quantified, and their number and severity were found to increase, especially after grafts had been in place for 4 weeks. Although this coincided with the development of spermatogenesis, the extent of germ cell differentiation negatively correlated with severity of the lesions.

Association between age and epididymal and accessory sex gland function and their relation to sperm motility

Increased male age has been associated with significant reduction in pregnancy rates. This study investigated the association between age, the function of epididymal and accessory sex glands, and their relation to sperm motility. Ejaculates from 498 men assessed for infertility were analysed according to WHO [1999] guidelines. Seminal markers of epididymal (neutral alpha-glucosidase (NAG)), prostatic (prostate-specific antigen (PSA) and zinc), and seminal vesicle function (fructose) were measured. Four groups according to age were defined: G(21-30) (21-30 years), G(31-40) (31-40 years), G(41-50) (41-50 years), and G(>50) (51-66 years). Percentage progressive motility was significantly lower in G(>50) compared with G(21-30). NAG, PSA, zinc, and fructose were significantly lower in G(>50) compared with G(21-30). In a multiple regression analysis model, NAG and PSA showed positive significant association with percentage progressive motility. The opposite trend was found regarding zinc. No association between fructose and percentage progressive motility was shown. In this cross-sectional study, declined sperm motility observed in men over 50 years of age might be due to age-dependent changes in epididymal and accessory sex gland function.

Photoperiod-induced apoptosis in the male genital tract epithelia of the golden hamster

The aim of this study was to identify some details of the changes induced by a short-day light regime (8:16 light:dark) on the male genital tract and accessory sex glands of the golden hamster Mesocricetus auratus. We principally examined the presence of apoptotic cells in the epithelium from different regions of the epididymis, seminal vesicles, prostate and coagulating gland. We detected an increase in the percentage of apoptotic cells in situ using the TUNEL technique in animals that were maintained for 6, 8 or 12 weeks in a short photoperiod. That those cells were indeed undergoing apoptosis was confirmed by the immunodetection of the active fragment of caspase-3. The apoptotic indices in the different tissues analysed were low, but were maintained for weeks, suggesting cell loss at a steady rate. We tried to correlate these changes with the testosterone levels in serum as well as with the oxidative stress in the tissue. On the other hand, the increase in size and number of lipofuscin granules indicated the possibility that a parallel increase in oxidative stress occurred in the tissues. The normalization in the number of apoptotic cells and lipofuscin granules in animals treated with testosterone suggests that both phenomena might be related to changes in the hormone levels.

Induction of apoptosis by castration in epithelium of the mouse seminal vesicles

Castration on days 0, 5, 10, 20, 40, and 60 caused increases in an apoptotic index (% of apoptotic cells) in seminal vesicle (SV) epithelium, peaking 1-3 days after castration. The peak apoptotic indices after castration on days 0, 5, 10, and 20 were significantly lower than peak apoptotic indices observed after castration on days 40 and 60. DNA extracted from mouse SVs 2 days after castration on days 0, 5, 10, and 60 showed a ladder pattern on agarose gel electrophoresis. The secretion of androgen by testes was confirmed by the growth retardation of the SVs after castration on days 0, 5, 10, and 20. It would appear that a proportion of SV epithelial cells dependent on testicular androgens for survival is smaller before day 20 than after day 20.

Age-induced apoptosis in the male genital tract of the mouse

We have examined the effects of ageing on the increase in apoptotic cells numbers in the male genital tract of the house mouse (Mus musculus). We have found that not all organs have the same response. There is an induction of apoptosis in both the epididymis and ventral prostate. However, seminal vesicles and other prostatic lobes remain unaffected. Apoptosis was assessed by several methods: TUNEL, detection of the active fragment of caspase-3 and the pattern of DNA fragmentation on agarose gels. This increase in apoptosis is related to the fall in testosterone levels, although there is only a partial decrease in androgen receptor (AR). AR is still present in all tissues and only moderately reduced in the epididymis and ventral prostate. A more intense increase of lipofuscin granules, which may be indicative of oxidative stress, occurred in these tissues. Finally, testosterone supplementation reverses the changes (both in apoptosis and lipofuscin content in the tissue), suggesting a role of androgens in these processes.

Abdominal temperature induces region-specific p53-independent apoptosis in the cauda epididymidis of the mouse

It is widely accepted that temperature regulates gene expression and function in the epididymis. However, the significance of reduced temperature of the scrotum in cell survival had not often been examined. Our hypothesis was that the experimental increase of the temperature could induce apoptosis. Using a surgical method that consists of surgically reflecting the cauda epididymidis in the abdomen, we have been able to show that this is the case. Apoptosis was examined by histologic procedures and by visualization of DNA fragmentation in agarose gels. We determined that the apoptosis is region-specific and affects only the principal cells of the proximal region of the cauda. It starts 12 h after surgery and ends by the third day. The apoptotic cells are eliminated by extrusion into the lumen and phagocytosis by adjacent cells. The complete molecular mechanism of apoptosis in this case remains unknown, but we have used the techniques of immunocytochemistry, Western blot, and reverse transcription-polymerase chain reaction to determine the role of some molecules. We have seen no significant role of androgens, the tumor suppressor p53, nor two heat shock proteins, hsp-25 and hsp-70. Nevertheless, we have detected a strong induction of bax and bcl-2 gene products. While the former should be responsible for the apoptosis observed, the latter would promote the survival of most of the cells of the cauda epididymis.

Cryptorchidism in mice mutant for Insl3

Impaired testicular descent (cryptorchidism) is one of the most frequent congenital abnormalities in humans, involving 2% of male births. Cryptorchidism can result in infertility and increases risk for development of germ-cell tumours. Testicular descent from abdomen to scrotum occurs in two distinct phases: the trans-abdominal phase and the inguino-scrotal phase. Currently, little is known about the factors that regulate the trans-abdominal phase of testicular descent. Leydig insulin-like hormone (Insl3) is a member of the insulin hormone superfamily expressed in the developing testis. We show here that mice mutant for Insl3 are viable, but exhibit bilateral cryptorchidism due to developmental abnormalities of the gubernaculum, resulting in abnormal spermatogenesis and infertility. Female homozygotes have impaired fertility associated with deregulation of the oestrus cycle. These findings reveal roles for Insl3 in the development of the urogenital tract and in female fertility. Insl3 may act as a hormone to regulate the growth and differentiation of the gubernaculum, thereby mediating intra-abdominal testicular descent.