ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01187.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryTo investigate in real time if and how natural gravity affects rates of swim‐up and swim‐down of human spermatozoa, samples of motile or immobilized spermatozoa in a sealed mini‐chamber were placed vertically on a 90° tilted microscope. The mode of their sedimentation, as well as the difference in the rate of their swimming up and down, were observed directly over 30 min and analysed from photomicrographs. Under the influence of natural gravity force, most immobilized spermatozoa turned their heads down in about 5 min and then sank slowly at an average speed of 0.2 μ/s. The number of motile spermatozoa that swam down was 5–6 times more than those swimming up. It can be implied that in spite of the mild force exerted by 1gon suspended spermatozoa in comparison to the high g force obtained by centrifugation, the overall effect of gravity on the rate of swimming up or down becomes dominant. Gravity causes the sperm heads to turn downward after which the oriented spermatozoa continue to move down by their own tail movements, causing accumulation of motile spermatozoa at the bottom. This may explain why in some recent studies swim‐down was superior to the swim‐up procedure during sperm separation by s

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01188.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryCapacitation of spermatozoa is essential for fertilization, and can be induced by various agents or biological fluids. Previous reports have shown that foetal cord serum (FCS) and the superoxide anion trigger human sperm hyperactivation and capacitation, and that superoxide dismutase (SOD) prevents these processes. We investigated: (1) the capacity of seminal plasma (SP) and follicular fluid (FF)(whole, or fractionated into high and low molecular weight components), in the presence or absence of SOD, to induce the spontaneous acrosome reaction(no stimulant needed, AR) and capacitation (as measured by the lysophosphatidyl‐choline‐induced AR, LPC‐AR); (2) a possible relationship between the levels of AR and capacitation obtained with these biological fluids and the superoxide scavenging capacity of the same fluids. The highest levels of LPC‐AR were obtained with FF ultrafiltrate (48 ± 6%), followed by SPultrafiltrate (31.9 ± 0.8%), FF (30 ± 5%), dialysed FF (27 ± 4%), and finally, by FCSultrafiltrate (23 ± 1%.), SP (21 ± 1%) and dialysed SP (18.9 ± 0.8%).A similar order of potency for the fluids existed when sperm AR was studied, the levels of AR observed ranging from 26 ± 2% to 5.3 ± 0.8% after incubation with FF ultrafiltrate and SP respectively. None of these treatments had detrimental effects on sperm motility. In the presence of SOD, there was always an important reduction (52–86%) of the AR and LPC‐AR observed. A highly significant inverse linear relationship was observed between the SOD‐like activity of the fluids tested and the AR (r= 0.86, p<0 0.001) and LPC‐AR (r= 0.91, p<0.001)observed in the presence of these fluids. The results suggest that biological fluids contain inducers of the AR and capacitation, and that these probably act by a common mechanism, possibly by direct or indirect induction of an NADPH oxidase in the sperm membrane. The data suggest strongly that the SOD‐like activity of a specific fluid is probablyone of the most important factors that will determine its capacity to indu

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01189.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryThe aim of this study was to undertake a morphological analysis of the earliest stages of experimentally induced (by genital ridge grafting) germ cell tumours in mouse strains with (129/Sv‐ter) and without (MA) spontaneous tumorogenesis. Genital ridges from fetuses aged 12 or 13 days from129/Sv‐terand MA were transplanted into the testes of adult129/Sv‐ter. The results show clearly that experimentally induced carcinoma‐in‐situ in mouse testes differs considerably from its human counterpart, found in patients with and without testicular germ cell tumours, and considered to be the precursor for all kinds of germ cell tumours of the adult testis apart from spermatocytic seminoma. The results indicate that development of testicular germ cell tumours is different in man and

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01190.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryBlood samples were obtained from the testes of rats, guinea pigs and Macaque monkeys and from normal men undergoing vasectomy reversal, in order to assess the comparative dynamics of hormone secretion. In each species, blood was sampled from a vein on the surface of the testis (testicular venous blood, TV), from a vein in the spermatic cord above the pampiniform plexus (spermatic venous blood, SV) and from a vein elsewhere in the body (peripheral venous blood, PV). Plasma concentrations of testosterone and inhibin were then determined by radioimmunoassay. In all species, testosterone secretion profiles were comparable, with concentrations being greatest in TV blood. SV concentrations were reduced by 40–60% compared with TV levels, with a significantly greater reduction in PV levels. Inhibin secretion varied significantly between species, with the rat being the only animal to show significant increases in inhibin concentrations from TV to SV blood. Inhibin secretion in the guinea pig was most comparable with that of the rat, although the increased SV levels fell short of being significant. Macaque and human profiles contrasted with those of the rat and guinea pig, with the greatest inhibin concentrations being found in TV blood. Levels in SV blood were reduced by some 40%, and PV levels were reduced significantly further. These differences may be due to the different position of the rete testis, and its relationship to the testicular vasculature, in these species. The sampling procedure described provides a defined set of testicular blood samples that could contribute important information of relevance to physiological and clinical studies of testicular function. Hormone concentrations in TV blood samples provide the most accurate indication of intratesticular levels, and the present study demonstrates that TV blood can be sampled with relative ease from a major vein on the surface of the human testis. The observation that testosterone and inhibin concentrations in TV blood were 10 or 250 times greater, respectively, than in PV blood in men, suggests that greater clinical use of this sampling procedure may be warranted when surgical intervention is taking place for other reasons, as this could give insight into the pathophysiology of the human testi

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01191.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryExperimental autoimmune orchitis (EAO) was induced in adult Wistar rats by active immunization with a testicular homogenate (TH) and adjuvants. Fifty per cent of the immunized rats developed EAO. Testicular damage became evident at 50 days after the primary immunization and increased in severity at 80 days. Phenotypic characterization of T‐cell subsets (CD4+ and CD8+) and Ia+ cells was performed on cryostat sections of testis obtained from normal rats, rats immunized with adjuvant (control group) and rats immunized with TH and adjuvants (experimental group) at 50 and 80 days. Labelled cells were only detected in the interstitial area; no labelled cells were observed inside the seminiferous tubules with any of the monoclonal antibodies used (W3/25, OX‐8, OX‐6). A significant increase in the numbers of CD4+ and CD8+, as well as of Ia+ cells, were observed in the testis of rats with severe EAO at 80 days after the first immunization. Rats of the same experimental group without testicular damage showed no major differences compared to rats from the control group, with the exception of a lower number of CD8+ cells. Variations in the lymphocyte subsets in lymph nodes draining the site of immunization showed the opposite pattern to that observed in the testis. In conclusion, these data suggest the traffic of specifically sensitized lymphocytes from lymph nodes to the testis and an active role of CD4+, CD8+ and Ia+ cells in the pathogenesis of EAO in th

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01192.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryTwo‐dimensional polyacrylamide gel electrophoresis (2D PAGE) was used to analyse [35S]‐methionine‐labelled proteins secretedin vitroby Sertoli cells when cultured in the presence or absence of enriched preparations of pachytene spermatocytes (SPC), early spermatids (SPT) or residual bodies/cytoplasts from elongated spermatids (RB/CES). The presence of germ cells modified the pattern of Sertoli cell secreted proteins in co‐culture. Out of 21 Sertoli cell secreted polypeptide families visualized by 2D PAGE, one (referred to as number 12) was stimulated, whereas the secretion of polypeptides 1 and 3 was inhibited by all of the germ cell populations tested. Early spermatids and RB/CES both enhanced the secretion of protein number 10 and inhibited the production of protein 11. The RB/CES fraction specifically inhibited secretion of polypeptide 13. Of particular note was the finding that co‐culture with early spermatids or RB/CES induced the secretion of a novel polypeptide, termed GIP (germ cell‐induced protein), with an apparent molecular weight of 72 kDa and an isoelectric point of 5.9. Under the present experimental conditions, media conditioned by the different germ cell fractions inhibited the secretion of polypeptide 2 but enhanced the secretion of polypeptides 10 and 18; of note also was the finding that media conditioned by early spermatids or RB/CES induced the appearance of GIP. This study confirms and extends the concept that germ cells influence Sertoli cell function and that the effects observed differ according to the stage of development of the germ cells. However, the sensitivity of the 2D gel electrophoresis technique, and to some extent its reproducibility, limit its use for studying the paracrine control of Sertoli cells

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01193.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1993.tb01194.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY