ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00463.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummarySince the development of surgery, the possibility of testis transplantation has fascinated man for centuries. Hunter and Berthold are considered to be the most important investigators in this field and, in addition, to be the founders of modern endocrinology. The association of testis transplantation with rejuvenation led to widespread popularity for this treatment in the first three decades of the twentieth century. At the same time, controversies concerning the aim of the treatment have coloured the early years of endocrinology. In the 1960s renewed interest in the subject arose for experimental reasons, leading to the development of microsurgical techniques for autotransplantation of high‐lying undescended testes in children. Homologous testis transplantation has never become a subject of great interest, probably for ethical reasons. This possible treatment for hypogonadism, however, has been developed experimentally and has been performed in man only in Russia and China, evidently with success. The details of these studies and their outcomes are discusse

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00464.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryInformation on the organization of the spermatogenic cycle of the common marmoset (Callithrix jacchus), a small New World primate, is limited to a single histological report on the differentiation of spermatids. In the present study we have used non‐radioactive in‐situ hybridization with a cRNA probe directed against marmoset protamine 2, on fixed sections of marmoset and human testis to elucidate the organization of mature germ cells within the seminiferous epithelium. Specificity of the probe was checked on Northern blots; mP2 hybridized exclusively to mRNA in samples extracted from marmoset and human testis. In sections from human and marmoset testis, positive staining for mRNA was confined to round and elongating spermatids and in the human was reduced in samples from patients with incomplete spermatogenesis. In the human, P2 mRNA was present in groups of cells consistent with the presence of more than one stage of the spermatogenic cycle in transverse sections of individual tubules. In the marmoset, P2‐positive cells were detected as a continuous ring of staining in the majority of sections of tubules whilst in others only a group(s) of cells was positive. We conclude that the arrangement of the spermatogenic wave in this New World primate may be intermediate between that seen in rodents (segmental) and in the human (hel

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00465.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryAdult intact control rats, and animals treated with human chorionic gonadotrophin (hCG) or with ethane dimethane sulphonate (EDS) to deplete Leydig cells, were injected with bromodeoxyuridine (BrdU) to label proliferating cells. Apoptotic cells were visualized by in‐situ end labelling (ISEL) of fragmented DNA. Three per cent of testicular endothelial cells were labelled with BrdU and few were apoptotic in intact testes. The BrdU endothelial cell labelling index was increased by hCG‐treatment and decreased in Leydig cell‐depleted testes. Immunohistochemical staining showed that Leydig cells and testicular macrophages contain immunoreactive vascular endothelial growth factor (irVEGF). The ability of testicular cells to stimulate angiogenesis was studied further by transplanting interstitial cells or seminiferous tubule segments under the kidney capsule. A prominent vascular network was observed around interstitial cell grafts, but not around tubule grafts. Treatment of transplanted rats with human chorionic gonadotrophin (hCG, 50 i.u.) resulted in an accumulation of PMN‐leukocytes and an increase in vascular permeability in the remaining testis and in interstitial cell grafts. Interstitial cells from Leydig cell‐depleted (EDS‐treated) testes were also transplanted under the kidney capsule. This type of graft caused only a discrete stimulation of angiogenesis, and there was no increase in vascular permeability around the graft after hCG treatment.It is suggested that Leydig cells secrete angiogenic factors and that they are the source of the inflammation mediator(s) produced in the testis after hCG treatment. The high proliferation rate in endothelial cells suggests continuous remodelling of the testicular microvasculature, but the functional significance of this rema

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00466.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryTreatment of adult male rats with human chorionic gonadotrophin (hCG) results in an inflammation‐like response in the testicular microcirculation. Polymorphonuclear (PMN) leukocytes accumulate in venules and vascular permeability is increased. The mechanism behind this response was studied. Treatment with an interleukin‐1 receptor antagonist partly prevented the hCG induced accumulation of PMN leukocytes 4 h after treatment. Human recombinant interleukin‐1α (IL‐1α) and β (IL‐1β), serotonin, and histamine were injected intratesticularly on one side and saline injected on the contralateral side in both intact and hCG‐pretreated adult rats. A low dose of IL‐α (a dose that did not increase vascular permeability in unstimulated testes) increased vascular permeability in the testes of animals treated with hCG 4, 6 or 8 h earlier, but it was without effect in testes from rats treated with hCG 0,1, 2, 16 or 32 h prior to IL‐1 injection. The sensitivity to the pro‐inflammatory effect of locally injected IL‐1β was also increased by hCG treatment. There was no increase in vascular permeability after local injection of a large dose of histamine or serotonin in either saline‐ or in hCG‐pretreated animals. Hypothetically, the hCG‐induced inflammation‐like increase in testicular vascular permeability could be related to increased sensitivity to constitutivel

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00467.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryThe involvement of apoptosis in germ cell degeneration in the adult rat testis after gonadotrophin suppression has recently been shown in several studies, which have focused on the localization of apoptotic cells to the stages of the spermatogenic cycle. However, the precise germ cell types and maturing steps at which apoptosis is elicited remain controversial.The present study used oestradiol treatment to produce hormone suppression and to study induced germ cell degeneration. Adult male rats were administered a daily injection of 50 μg oestradiol benzoate for 5, 10 or 15 days. Characterization of the ultrastructural features of the dying cells and in‐situ 3′‐end labelling of DNA showed clearly that the deaths of all the germ cell types occurred by apoptosis. High‐resolution light microscopy, although time‐consuming, resulted in a precise method for analysis of the localization of the cells involved. Stages IV–X of the seminiferous epithelium were found to be the most sensitive to degeneration in response to oestradiol treatment. Our results are discussed in the light of current knowledge about the hormonal control of the spermatogenic cycle. Oestradiol treatment has proved to provide a suitable in‐vivo model to study g

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00468.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryPhospholipase A2(PLA2, EC 3.1.1.4) is involved in the cascade of signalling events leading to the acrosome reaction in human spermatozoa. In order to study the role of PLA2in the acrosome reaction triggered by GTPγS, a non‐hydrolizable analogue of GTP, two well‐known PLA2inhibitory reagents were used: dexamethasone (1 mM, a synthetic glucocorticoid), and 2‐(p‐amylcinnamoyl)amino‐4‐chlorobenzoic acid (ONO‐RS‐082, 320 μg/ml). Normal human spermatozoa were incubated for 3 h under capacitating conditions and treated with several reagents [GTPγS, dexamethasone, ONO‐RS‐082, arachidonic acid (AA) and lysophosphatidylcholine (LPC)], alone or in different combinations. In confirmation of earlier reports, GTPγS induced the acrosome reaction. On the other hand, dexamethasone and ONO‐RS‐082 were both able to inhibit the acrosome reaction induced by GTPγS. However, when AA or LPC was added after dexamethasone or ONO‐RS‐082, the acrosome reaction reached values close to those obtained using GTPγS alone. It is concluded that PLA2probably plays an active role in the acrosome reaction

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00469.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SummaryHyperprolactinaemic male rats exhibit deficits in copulatory behaviour which can be reversed by a single injection of GnRH. We tested whether systemically administered GnRH can stimulate copulatory behaviour independently of LH‐mediated increases in plasma testosterone levels. Gonadectomized, pituitary‐grafted adult male Fischer 344 rats bearing implants of 5, 10 or 20 mm capsules of testosterone were administered a single injection of 500 ng GnRH or saline s.c., 30 min prior to copulation tests. Pituitary‐grafted castrates displayed copulatory deficits, relative to sham‐operated castrates with identical levels of testosterone replacement. Administration of 500 ng GnRH to pituitary‐grafted castrates bearing 10 mm testosterone implants significantly increased the proportion of rats that mounted, intromitted and ejaculated during a 30 min test. This treatment also reduced significantly the latency of intromission and ejaculation, and increased significantly the frequency of intromission. The copulatory behaviour of the sexually unresponsive, pituitary‐grafted castrates bearing 5 mm testosterone implants, or of the more sexually responsive castrates bearing 20 mm testosterone implants, was not altered significantly by GnRH injections. These results support the hypothesis that copulatory deficits in moderately hyperprolactinaemic rats are due in part to reduced hypothalamic GnRH release, and suggest that GnRH can stimulate sexual behaviour in these animals via mechanisms that are independent of luteinizing hormone‐induced testosterone release. However, a threshold level of testosterone (achieved with 10 mm implants) appears to be required for GnRH to elici

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00470.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00471.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1996.tb00472.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY