摘要:

Summary.Ultrastructural features and morphometric evaluations of water buffalo seminiferous epithelium are reported for the 6 phases of the spermatogenic cycle. The relative Sertoli cell volume varies between 30% (phase 4) and 39% (phase 8), the calculated volume of a Sertoli cell between 7118 μm3and 8968 μm3(phase 4). Smooth ER is the organelle that exhibits the most prominent changes in Sertoli cells during the spermatogenic cycle: it occupies about 6% in phase 3 and 21% in phase 4. All spermatogenic cells of the same clone present cytoplasmic bridges among them. From preleptotene (about 470 μm3) to late diplotene (about 2300 μm3) the volume of a primary spermatocyte increases nearly 5‐fold; their nuclear volumes increase 3.5‐fold in the same period. Secondary spermatocytes are found only in phase 4 of the cycle. Due to partial cell necrosis and autolysis late maturation phase spermatids display not more than 25% of the size of early cap phase spermatids. 63% of all numerically possible germ cells disappear from the seminiferous epithelium during spermatogenesis. Particularly heavy cell loss is observed in phase 4 and involves the spermatogonial fraction as well as cells during the second meiotic d

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02612.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.All four components of the kallikrein‐kinin system—kininogens, tissue kallikreins, kinins, and kininases—have been found in human male genital secretions. Kinins are continuously released from seminal plasma kininogens through limited proteolysis by kininogenases like tissue kallikrein from prostate and sperm acrosin. Kinins are the terminal effectors of the kallikrein‐kinin system and increase sperm motility and sperm metabolism at nanomolar concentrations. Recent investigations indicate that these effects are possibly mediated by a specific sperm membrane integrated bradykinin receptor, subtype B2. The two major kininases that are present in seminal plasma are kininase II and neutral metallo‐endopeptidase. Kininase II, which is identical with angiotensin‐converting enzyme, is also involved in the renin‐angiotensin system as it converts angiotensin I into angiotensin II and thus is the connecting enzyme of both systems. Apart from the observed effects of kinins on sperm motility, the kallikrein‐kinin system is thought to be involved in the regulation of spermatogenic functions of the testis: in the rat, kallikrein activates Sertoli cell function, increases the relative number of spermatocytes and the [3H] thymidine incorporation of testicular tissue, enhances glucose‐intake, and increases testicular blood flow. Clinical trials showed that systemic administration of kallikrein may be particularly useful for treatment of infertile men suffering from asthenozoospermia and/or oligozoospermia. During kallikrein therapy, the number of spermatozoa and both quantitative and qualitative sperm motility increased, and a significant improvement of the conception rate was achieved. An increased sperm number was also observed after application of the specific kininase II inhibitor captopril. Recent investigations proved intestinal absorption of porcine pancreatic kallikrein in men, supporting the clinical effectiveness of oral kallikrein therapy. Furthermore, the results indicate that absorbed kallikrein may be enzymatically active for hours in serum. Thus, according to the variousin vitroexperiments, animal studies, and clinical trials, there is increasing evidence that the kallikrein‐kinin system is involved in male rep

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02613.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Sperm nuclear decondensation is an integral step in fertilization which leads to the formation of the male pronucleus. The association between thein vitrospontaneous nuclear decondensation of human sperm and its fertilizing ability was studied in infertile male patients. The ability of sperm to fertilize an egg using the discontinuous two‐layer Percoll method was significantly correlated to the percentage of decondensed swollen head (r= 0.43;P<0.005). The fertilizing ability of sperm processed with Test‐Yolk buffer was correlated with the percentage of sperm at the fully decondensed stalk stage (r= 0.51;P0% fertilization) in the sperm penetration assay had a higher percentage of decondensed sperm heads (66.7% vs. 20.6%) after Percoll wash or whole‐wash centrifugation (60.5% vs. 44.3%) treatments compared with samples with no fertilization. Treatments that included Test‐Yolk resulted in high percentages of decondensed swollen heads. The results suggest a positive association between sperm nuclear decondensation and the fertilizing ability of sperm, and affirm the importance of nuclear decondensation to the study of fertili

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02614.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Incubation of human spermatozoa in capacitation media for 24 h results in a significant increase in acrosome reacted spermatozoa as compared to preincubation (baseline) levels. By contrast, sperm samples recovered from the cervix for as long as 72 h after coitus only showed baseline percentage of acrosome reacted spermatozoa. These results indicate that spermatozoa do not undergo the acrosome reaction during cervical storage and suggest that cervical mucus suppresses the spontaneous acrosome reaction of spermatozoa that become capacitated in the cervix.

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02615.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary We fractionated the whole human seminal plasma on DEAE Sephadex A‐50 ion exchange columns. Complete separation was achieved in seven peaks using different salt concentrations in phosphate buffer pH 6. The seminal plasma proteins were separated by sodium dodecyl‐sulphate polyacrylamide gel electrophoresis. Human seminal plasma (SP) and its fractions were used in mixed lymphocyte reactionin vitro.Fractions 3, 4, and 7 were found to suppress the proliferation of human peripheral blood mononuclear cells to phytohemagglutinin and pokweed mitogen at a concentration of 10 μg ml−1while stimulatory effect was observed at lower concentrations (1 μg and 2.5 μg ml−1). Whole human SP and other fractions failed to suppress the proliferation of lymphocytesin vitro.Furthermore, the effect of human SP and its fractions was also investigated on phagocytic function of polymorphonuclear leukocytes (PMNs) using luminol dependent chemiluminescence assay stimulated with phorbol myristate acetate and opsonized yeast. Fractionated SP was found to have a suppressive effect on the luminol‐dependent chemiluminescence of PMNs in t

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02616.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Seminal quality and levels of blood serotonin (5‐HT) and serum prolactin (PRL) were determined in 60 men attending an infertility service. Subjects were grouped according to normal or abnormal accessory sex gland function.Subjects with normal accessory sex gland function were further subdivided into groups with asthenozoospermia, polyzoospermia, normozoospermia, oligozoospermia, or azoospermia. Blood 5‐HT levels were significantly higher in oligozoospermics (115.9 ± 23.7 ng ml−1,P<0.05), and asthenozoospermics (90.0 ± 8.2 ng ml−1,P<0.05), than in normals (68.5 ± 5.3 ng ml−1), whereas serum PRL levels were higher in azoospermics (44.2 ± 4.7 ng ml−1) than in normozoospermics (15.9 ± 1.6 ng ml−1,P<0.01).Subjects with abnormal accessory sex gland function were also subdivided according sperm count and sperm motility categories. None of these subgroups showed differences in serum PRL levels or blood 5‐HT levels.Men with hyperserotoninaemia had higher serum PRL levels, low sperm count, and low motile sperm concentration. Moreover, higher 5‐HT levels may be observed in men with normal PRL levels and also associated with normal PRL levels and with hyperprolactinaemia, and hyperprolactinaemia may be observed also associated with normal serotonin levels.Hyperserotoninaemia was related to both diminished sperm count and sperm motility, whereas hyperprolactinaemia was related to low sperm count. When hyperprolactinaemia and hyperserotoninaemia were both present, additive

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02617.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Metoclopramide (MCP) in doses of 2.2 mg kg−1body weight, being administered intraperitoneally to rats for 14 d, provokes a premature release of germ cells in the testes. The number of spermatozoa is reduced. In addition the spermatozoa exhibit defects of head and tail structures. After the administration of MCP for 14 d, followed by a 14‐d break in applying the drug, the number of spermatozoa in the lumen of the epididymal duct continues to be low. Many spermatozoa are damaged. Only after a 66‐d‐break in MCP administration is the morphology of the seminiferous epithelium restored, and a large number of spermatozoa appear in the lumen of the epididym

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02618.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.In addition to the well‐known control circuits involved in the regulation and adaptation of testicular androgen biosynthesis, it is proposed that two new control strategies are involved in the maintenance of steady‐state testosterone secretion rates by testicular Leydig cells. Cytochrome P450XVII (steroid‐17α‐monooxygenase/steroid‐17,20‐lyase), one key enzyme in steroid hormone biosynthesis, responds to external human choriogonadotropin stimulation with an oxygen‐dependent and substrate flux‐dependent inactivation and decomposition, and increased substrate availability decreases the efficiency of androgen formation in favour of abortive intermediate leakage. These results are discussed as a paradigm of substrate‐dependent modulation of cytochro

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02619.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.Flutamide, a pure antiandrogen, increases the levels of plasma luteinizing hormone but antagonizes the biological expression of androgen on target organs. Flutamide was administered to rats to study the effect of altered availability of hormones on the functional status of epididymis. The weights of ventral prostate, seminal vesicles and epididymis showed antiandrogenic effects of flutamide. However, increased activity of kidney β‐glucuronidase reflected increased availability of testosterone. The concentrations of protein and DNA along with the activities of acid phosphatase and hyaluronidase decreased in flutamide‐treated rats. The activities of acid phosphatase and hyaluronidase in epididymal sperms along with protein concentration increased in flutamide‐treated rats. Alteration of epididymal function by treatments affecting lysosomal stability was ind

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02620.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Summary.We report on a young boy who developed gynaecomastia 15 months before he showed clinical manifestations of sexual precocity. He was treated with medroxyprogesterone acetate with good results. His development to adulthood is presented. The causes of gynaecomastia in the prepubertal child are reviewed.

ISSN:0303-4569    

DOI:10.1111/j.1439-0272.1992.tb02621.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY