摘要:

SummaryEarlier studies have demonstrated that pentoxifilline (PTX) and platelet‐activating factor (PAF) can significantly improve the motion parameters of post‐thaw human spermatozoa. This study has investigated the effects of PAF, PTX and their combination on cyclic adenosine monophosphate (CAMP) concentrations and membrane lipid peroxidation (LPO) in post‐thaw human spermatozoa. Washed spermatozoa from normal volunteers (n=10) were cryopreserved in Test‐yolk buffer using a standard protocol. After 2 weeks the sperm samples were thawed, washed and incubated with either 1 p˜ PAF, 3 m˜ PTX or 0.5 p˜ PAF plus 1.5 m˜ PTX. Video sequences were recorded at 0, 30, 60, and 120 min for analysis of sperm motion parameters using the Cell Track Sperm Analysis System. Concentrations of cAMP were assessed by radioim‐munoassay, and LPO levels were measured by malondialdehyde‐thiobarbituric acid reactivity. Our studies indicate a time‐course stimulatory effect with overall maximal stimulation observed in samples treated with the combination of PAF and PTX. The maximal stimulation of percentage motility compared to control was observed at 60 min in samples treated with PAR PTX, or PAF plus PTX. PAF plus PTX stimulated straight‐line velocity (VSL), curvilinear velocity (VCL) and lateral head displacement (ALH) after 30 min incubation. The primary effect of PAF was observed on VSL, while the main effect of PTX was on VCL. CAMP concentrations were 3‐fold higher than controls in samples treated with PTX or PAF plus PTX. CAMP concentrations in PAF‐treated samples did not differ significantly from controls. No significant differences were observed between any groups for LPO. This study demonstrates that both PAF and PTX can improve the motion parameters of post‐thaw human spermatozoa with the maximal effect observed by their combination. The stimulatory effect of PTX in these post‐thaw samples is related to increased CAMP levels, while another mechanism is likely to be operational for PAR Protection from lipid peroxidative membrane damage is not suggested to be the mechanism of action for PAF or

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01238.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryCellular interactions in the testis and epididymis are an important prerequisite for spermatogenesis and sperm maturation, and involve a well‐developed complex of intercellular junctions. Cadherins are cell surface proteins which mediate intercellular Ca2+ ‐dependent adhesion and are believed to be fundamentally important for maintaining multicellular structures. In the present study we report the expression of a 135 kDa N‐cadherin polypeptide in the human seminiferous epithelium by immunoblotting. The presence of N‐cadherin was demonstrated by immunohistochemistry on the surface of spermatogonia and primary spermatocytes, and possibly also around some early spermatids, whereas late spermatids were always negative. Endothelial cells also stained for N‐cadherin, whereas peritubular cells and Leydig cells did not. No expression of E‐cadherin could be demonstrated in the human testis. In the human epididymis E‐cadherin, but not N‐cadherin, was expressed and localized to the surface of the principal epithelial cells as shown by immunohistochemistry. These observations indicate that cadherins play an important role in the organization of the seminiferous and epidid

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01239.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThis study assessed the condition of spermatozoa from the proximal vas deferens of men after vasectomy. The fluids of both proximal vas deferens were collected from 67 vasectomized men by cannulating the vas deferens at the time of vasectomy reversal. Selected sperm parameters were analysed after incubation of the spermatozoa for 30 min at 37°C. Spera concentration in the proximal vas from vasectomized men (16 312 ± 21 496 million per ml, geometric mean: 7948 ± 398 million per ml) was significantly higher than that of fertile men and was maintained at a constant level independent of the duration of vas obstruction. The means of sperm motility (36.2 ± 26.2%), spermatozoa with normal morphology (50.7 ± 21.7%), sperm viability (53.0 ± 25.3%) and hypo‐osmotic swelling test (HOS‐test, 53.9 ± 21.7%) were statistically lower than the respective values for normal fertile men. There was no significant correlation between the duration of vas obstruction and the above semen parameters. In 46.4% of vas fluids all spermatozoa were immotile and this condition was more common after 3 years of vasectomy. Immotile spermatozoa in the proximal vas fluids at the time of vasectomy reversal may be an important factor for predicting semen quality and fertilizing ability after vasovasostomy. There were no significant differences in the results of sperm‐cervical mucus penetration test (CMPT) between spermatozoa fiom vasectomized and fertile men. Antisperm antibodies on the surface of spermatozoa from the vas of vasectomized men were determined by the immunobead test (IBT; 78.6% for IgG, 32.1% for IgA) and sperm cervical mucus contact test (SCMC, 36.4%). The presence of antisperm antibodies on the spermatozoa from the vas of vasectomized men may explain, in part, the lower pregnancy rate after vasovasostomy. These parameters of spermatozoa from the proximal vas of vasectomized men may closely reflect those in the cauda epididymis aft

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01240.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryA preliminary assessment of the contraceptive efficacy of a daily mild increase (1–2°c) in testicular temperature during waking hours is reported in nine couples using two techniques of non‐surgical fixation of the testes close to the inguinal canal. With technique 1, immobilization was achieved by passing the penis and the empty scrotum through a hole made in close‐fitting underwear; there was one pregnancy, hm a man who stopped the heating after 7 weeks, for 42 cycles of exposure in three couples. With technique 2, immobilization was achieved by adding a ring of soft material surrounding the hole in the underwear; there was no pregnancy for 117 cycles of exposure in six couples. Reversibility and safety were assessed. These preliminary results suggest that a daily mild increase in testicular temperature could be a potential contraceptive method f

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01241.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryLeydig cell function was investigated in 71 men with idiopathic oligospermia and compared to 14 fertile controls by assessing the steroidogenic response to GnRH and the repetitive administration of hCG (1500 IU X3). The oligospermic men were divided into two groups according to their basal serum FSH values (FSH8,n=36), this level being defined by the mean + 3 SD of the levels in normal men (3.71+4.08 mIU/ml). Oversecretion of LH was supported by the findings of: (a) higher basal LH levels (p<0.0001) in both oligospermic groups, although still within the normal range; (b) higherDmaxLH and area LH (p8 group; (c) a strong position correlation (p<0.001) of the above parameters with the respective levels of FSH. No difference in basal testosterone levels was observed between the three groups, whereas basal levels of 17‐OHP were sigdcantly higher (p8. The testosterone/LH ratio was significantly (p8 group, and was correlated inversely to the basal blood levels of FSH<0.0001) and to the area LH (p<0.04). After the hCG test, there was no difference in the testosterone and oestradiol response between the groups, whereas the secretion of 17‐OHP and the ratio of 17‐OHP/testosterone was sigdcantly higher (p8 compared with the other two groups. Using multiple regression, the total production of 17‐OHP and the 17‐OHP/testosterone ratio were found to be correlated positively with FSH levels. These results support the view that in men with idiopathic oligozoospermia associated with severe Sertoli cell dysfunction there is parallel oversecretion of LH and compensated dysfunction of the Leydig cells, as indicated by oversecretion or accumulation of 17‐OHP after hCG administration, and also by the low testosterone/LH ratio. This is possibly due to alterations in intratesticular paracrine factors deriving from the Sertoli cells, as suggested by the positive correlation between the altered steroidogenic indices and blood

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01242.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe number of cryopreserved human spermatozoa which penetrated zona‐free hamster oocytes afier stimulation with 2μmol A23187 per litre was increased by the hrther addition of 0.6 or 3.6 mmol pentoxifjrlline per litre. With spermatozoa prepared by washing by repeated centrifugation, the median numbers of sperm headd/egg were 1.9, 7.9 and 10.8 in the presence of 0, 0.6 or 3.6 mmol pentoxifylline per litre, respectively. A similar effect was observed with spermatozoa prepared on a Percoll gradient. As A23187 inhibited sperm motility, and this was exacerbated by pentoxifylline, the increased penetration rate of hamster oocytes cannot be explained by improved sperm motility. The number of spermatozoa stimulated to acrosome react by 2 μmol A23187 per litre was increased 3‐fold by 3.6 mmol pentoxifylline per litre and 4‐fold by 5 mmol caffeine per litre. These data suggest that CAMP may act synergistically with Ca2+to stimulate the acrosome reaction. Pentoxifjrlline may improve the fertility of poor‐quality human spermatozoa by enhancing their ability to respond to the Ca2+signal produced by binding to the zona

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01243.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryIn vivomicroperifbsion and micropuncture were used to study tubule protein synthesis and proluminal secretion by the male reproductive tractin vivo. Somniferous and caput and cauda epididymal tubules were perihsed for 3 h. with [35S]‐methionine. Perifused interstitial fluid (IF), lumen fluid (LF), and tubule extract (TE) were collected. Proteins were separated by SDS‐PAGE, and autoradiograms were developed.Trichloroacetic acid precipitable proteins in each fluid were determined and a protein synthesis index (PSI) was calculated. PSI values demonstrated that the cauda epididymis synthesized less proteinin vivothan did either seminiferous or caput tubules.Seminiferous tubules synthesized and secreted into the tubule lumen a relatively constant panel of proteins. Epididymal tubules synthesized and secreted proteins in a region‐specific manner. In the caput epididymis the most prominent secreted bands were consistent with the heavy and light chains of epididymal clusterin. In the cauda epididymis, the most prominent synthesized and secreted protein was a 25 kDa protein consistent with the protein D. The above approach to studying protein synthesis and secretion will allow direct study of the physiological and path physiological effects on this important epithelial hnction

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01244.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe immunohistochemical localization of proliferating cell nuclear antigen (PCNA) has become a widely used method for the detection of proliferating cells in cancerous tissues. PCNA expression is maximal around the S phase of the cell cycle. This study has evaluated the applicability of PCNA localization for the analysis of germ cell proliferation in rats, Djungarian hamsters, rhesus and cynomolgus monkeys and men, using Bouin's‐fixed, paraplast‐embedded tissue. In addition, involuted testes from photoinhibited hamsters, testes from immature rhesus monkeys and from GnRH antagonist‐treated rats and cynomolgus monkeys were included. Monoclonal mouse anti‐PCNA antibody (clone: PC10) was used for detection of the antigen. Visualization was performed by immunogold‐silver staining or avidin‐biotin staining. PCNA labelling was confined to the nuclei of spermatogonia and early spermatocytes within the seminiferous epithelium of all species. The distribution of PCNA among the different types of A‐spermatogonia in primates is in good agreement with the previously described proliferation pattern of these cells. No staining was observed in resting A‐dark spermatogonia, while differentiating A‐pale spermatogonia were positive at distinct stages of the seminiferous epithelium cycle. In the rodent species the pattern of labelled A‐spermatogonia was stage‐specific, but agreed only partly with the previously described pattern of mitotic figures of A‐spermatogonia. Hormonal withdrawal induced a decrease in the number of PCNA‐positive cells in adult rats, hamsters and monkeys. In immature testes from rhesus monkeys positive staining was present in spermatogonia but also in some Sertoli cells, indicating proliferative activity of Sertoli cells in the prepubertal stage. It is concluded that PCNA localization can be used to assess the proliferative status of the renewing spermatogonia in the primate testis and to analyse the proliferative activity of the seminiferous epithelium under var

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01245.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1994.tb01246.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY