摘要:

SummaryThyrotrophin‐releasing hormone (TRH) and related peptides occur in high concentrations in human semen. TRH derives from a 242‐amino acid precursor protein, prepro‐TRH, with six repetitive sequences of‐Lys‐Arg‐Gln‐His‐Pro‐Gly‐Lys/Arg)‐Arg‐connected by hydrophobic linking sequences. Antibodies to TRH‐Gly (pGlu‐His‐Pro‐Gly), a final precursor for TRH formation, were used to detect this tetrapeptide as well as other prepro‐TRH fragments which cross‐react with these antibodies. The total TRH‐Gly immunoreactivity decreased significantly after vasectomy. The TRH‐Gly immunoreactivity in semen increased significantly during in‐vitro incubation at 0 or 37d̀C, to a peak value at 5 h, followed by an exponential decline, with t1/2equal to 11 h at 37d̀C. At 60d̀C, however, the TRH—Gly immunoreactivity rose continuously, attaining, after 20 h, a level 2.2 times that at the start of the incubation (P<0.001). Reversed‐phase high pressure liquid chromatography (HPLC) revealed both hydrophobic and hydro‐philic TRH‐Gly immunoreactive peptides in semen with both classes of peptides increasing significantly with heating to 60d̀C. Cation exchange chromatography of pooled human semen incubated at 60d̀C revealed a 4.3‐fold increase in a TRH‐Gly immunoreactive peak which co‐eluted with synthetic TRH‐Gly, and a 30% increase in another TRH‐Gly immunoreactive peak identified as Glu‐His‐Pro‐Gly. A minor, TRH‐Gly immunoreactive peak increased 50‐fold (P<0.001) during 20 h at 60d̀C. This material co‐eluted with Arg‐Gln‐His‐Pro‐Gly which is formed by enzymic cleavage of the paired basic residues flanking this sequence in prepro‐TRH. When synthetic Arg‐Gln‐His‐Pro‐Gly was incubated with fresh semen at 60d̀C a rapid conversion of most of this peptide to Glu‐His‐Pro‐Gly, Gln‐His‐Pro‐Gly and TRH‐Gly occurred within 30 min. These data are consistent with thermal inactivation of the amidation and degrading enzymes at 60d̀C while the trypsin‐like enzymes which cleave the precursor peptide at the paired basic residues remain relatively unaffected. Because other investigators have found the C‐terminal amidating enzymes to be associated with secretory vesicles and to be co‐secreted with the vesicular contents, we suggest that secretory epithelia of the male reproductive system secrete TRH and TRH‐related precursor peptid

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00974.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryWe examined the hypothesis that induction of reversible testicular atrophy, subsequent to withdrawal of gonadotrophin support, would alleviate the testicular toxicity of the anti‐cancer drug procarbazine. In rats, severe but reversible testicular atrophy and suppression of spermatogenesis were induced 56 days after the subcutaneous insertion of a silastic implant containing oestradiol‐17β. The effect of this treatment upon the testicular toxicity of four weekly doses of procarbazine (200 mg kg‐1) was examined 56 days after the termination of procarbazine/oestrogen treatment. At this time the testicular endocrine and sper‐matogenic functions were close to normal in rats which has received only oestra‐diol‐17β. Procarbazine produced severe testicular atrophy which was associated with azoospermia and destruction of the germinal epithelium. Serum LH and FSH concentrations were raised and were associated with low serum concentrations of both testosterone and androgen‐binding protein. The combination of procarbazine with the oestrogen treatment did not change any of the testicular toxicity and in some cases it appeared to be exacerbated. In contrast to these experiments other studies have indicated that the testis can be protected if spermatogenesis is revers‐ibly suppressed by other agents which are also active via the pituitary endocrine system. The data would therefore suggest that protection is achieved either by some testicular change other than withdrawl of pituitary gonadotrophin support or that oestradiol‐17β has additional activity which is permissive for the development of the testicular toxi

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00975.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThe effect of heat‐solubilized zonae pellucidae (ZP) isolated from mature pig ovaries on the conversion of pig proacrosin to acrosin was examined and compared with the effects of different sulphated polysaccharides. At low concentrations, zona glycoproteins potently stimulated acrosin auto‐activation. Up to 2.5 μg ml‐1ZP, the acceleration of acrosin activation was shown to be dependent on the ZP concentration. At higher concentrations zona glycoproteins exerted an inhibitory effect on acrosin amidase activity. A similar effect was demonstrated for fucoidan, heparin, and chondroitin sulphate. The results intimate thatin vivo, the conversion of proacrosin to acrosin is regulated at the sperm‐zona i

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00976.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryDifferent aspects of testicular microcirculation were studied in rats aged 20, 24 or 90 days, in order to determine if maturational changes in the testis could influence its vasculature. Using laser Doppler flowmetry, it was found that vasomotion was not present in 20‐day‐old rats, but it could be induced by hCG‐treatment given 32 h prior to flow measurements. In rats aged 24 days vasomotion was present in the testis but it was not influenced by hCG treatment, in contrast to adult rats in which testicular vasomotion disappeared after hCG treatment. In all age‐groups, hCG treatment induced an increase in testicular interstitial fluid (IF) volume, which was most pronounced in young rats. In young rats, as in adults, there was an increase in the volume density of polymorphonuclear (PMN) leucocytes in testicular blood vessels after hCG treatment. However, rats aged 20 or 24 days did not exhibit any significant extravascular migration of leucocytes as occurred in adult rat testis after hCG injection. The deposition of colloidal carbon particles observed in adult rats after hCG‐treatment was also not seen in young rats. It is concluded that the vasculature of the immature rat testis reponds to hCG stimulation with an increase in IF volume. However, when compared to adult rats, different mechanisms may be operating because no evidence for opening of inter‐endothelial cell gaps was observed in the testis of

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00977.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryMalvidin chloride (MC) a colouring agent from flowers ofMalvaviscus conzattiiGreenum was studied for male anti‐fertility effects in adult langur monkeys (Presbytis entellus entellusDufresne). When fed 50 mg MC kg‐1for a period of 60 days, inhibition of spermatogenesis resulted. The weights of testes and epididymides were reduced and there was atrophy of the Leydig cells. In the epididymis, epithelial cell heights were reduced after MC‐treatment. Conspicuous shrinkage of seminiferous tubules and Leydig cell nuclei were evident. Depletion of total proteins, RNA, sialic acid, alkaline/acid phosphatase activity in testes and epididymides with the elevation of testicular levels of cholesterol and glycogen also occurred. Blood/serum analysis and haematology of MC‐treated langur monkeys revealed that all of the clinically important parameters were well within the normal range. The slightly increased bilirubin concentration and alkaline phosphatase activity returned to normal range within 30 days of the last dose of MC. The anti‐spermatogenic activity of MC in langur monkeys is

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00978.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryTwo patients suspected of suffering from ciliary dyskinesis were investigated. They consulted for primary infertility and chronic respiratory disease. Functional lung studies showed obstructive changes in one patient. Both had immotile sperm with short, thick and rigid tails. Ultrastructural studies of nasal biopsies showed abnormal cilia with almost complete lack of inner dynein arms (mean number of inner arms per axoneme 0.67 ± 1.21 in patient 1 and 1.49 ± 1.17 in patient 2, compared with normal values of 5.3 ± 0.13). Other abnormalities included lack of parallel orientation of cilia and central translocation of microtubular doublets. Electron microscopy of sperm revealed hyperplasia of the fibrous sheath and axonemal disruption. This is the first report of an association of different anomalies in cilia and flagella leading to clinical manifestation of the immotile cilia syndrome. These findings emphasize the need for ultrastructural examination of respiratory cilia in men suffering from fibrous sheath alterations of sperm which so far have not been described in patients with the classical form of immotile cilia syndro

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00979.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryBioactive‐LH (B‐LH) was measured in plasma by in‐vitro bioassay and immunoactive‐LH (I‐LH) by immunoassay at 10 min intervals for 6 h in five men after standard chemotherapy for Hodgkin's disease. Eleven normal men acted as controls. Follicle‐stimulating hormone (FSH) was markedly raised in the treated patients (mean ± SEM; 12.8 ± 2.8 vs. 2.7 ± 0.4 IU 1‐1,P>0.006) reflecting damage to the germinal epithelium. Bioactive (27.4 ± 2.8 vs. 12.9 ± 1.3 IU 1‐1) and I‐LH (9.6 ± 2.0 vs. 4.9 ± 0.4 IU 1‐1) were elevated (P>0.006) in the patient group whilst testosterone levels (24.0 3.8 vs. 19.6 2.4 nmol 1‐1) were normal. The testosterone I‐LH ratio, a putative index of Leydig cell dysfunction, was negatively correlated with FSH levels (r=‐0.85,P>0.02). Bioactive and I‐LH pulse peak amplitude were elevated, as were pulse maxima (P>0.05). In contrast, B‐LH pulse frequency was similar between the patients (2 pulses per 6 h) and controls (median 2, range 1–3 pulses per 6 h) as was the I‐LH pulse frequency (median 2, 1–2 pulses per 6 h in both groups). The mean B:I LH ratios were similar (2.94 ± 0.09 vs. 2.63 ± 0.14) in both groups, although the inter‐pulse B:I ratio was increased (P>0.007) in the patient group. It is concluded that normal levels of testosterone are maintained in men with chemotherapy‐induced damage to the germinal epithelium by a resetting of the hypothalamic‐pituitary unit such that LH pulse amplitude but not the pulse frequency is increased markedly. The mean biopotency of LH remained uncha

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00980.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryChromatin zinc was studied using X‐ray microanalysis of spermatozoa obtained from split‐ejaculate fractions. Chromatin zinc, expressed as intensity ratio between zinc and sulphur (Zn/S), was unrelated to seminal zinc concentration, but was related inversely to markers of seminal vesicular secretion (fructose concentration and the proportion of zinc bound to ligands of seminal vesicular origin). It is concluded that the content of zinc in sperm chromatin can be reduced by the action of zinc ligands of seminal vesicular origin. An abnormally high contribution of seminal vesicular fluid to sperm‐rich fractions of the ejaculate thus creates a risk of depleting chromatin zinc and thereby impairing zinc‐dependent chromatin st

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00981.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThe present study describes the measurement of pH madein vivoin the rete testis fluid and in different regions of the boar epididymis. Furthermore, samples of whole ejaculates, semen fractions, testicular (ductuli efferentes/rete testis), epididymal and deferential fluids collected from the same fertile boars, were analysed for their acid/base status with an automatic blood gas analyser. A pH gradient of acidity was found between the fluid entering the ductus epididymis (pH 7.2) and the region of sperm storage at the cauda (pH 6.5). A significantly lower concentration of bicarbonate ion was found in the cauda epididymidis (3–4 mM) compared to rete testis fluid (30 mM), which might be related to the quiescence of the spermatozoa. A significant increase in extracellular pH and bicarbonate concentration occurred at ejaculation, the bicarbonate levels being 9–10‐fold higher in the semen fraction rich in seminal vesicle fluid, where sperm showed higher motility, than in the cauda epidi

ISSN:0105-6263    

DOI:10.1111/j.1365-2605.1990.tb00982.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY