Search PubMed⌕ Search

Biomedical subjects

S Fournier-Delpech

Publications and source records attributed to S Fournier-Delpech.

18 recordsLinked to original sources

Binding of rat and ovine epididymis-specific prealbumins (PES) to rat spermatozoa without effect of heterologous immunization on rat fertility.

The epididymis, under control of testosterone, secretes proteins which bind to the membrane of the spermatozoa during their passage through the lumen. One such class is termed PES (prealbumin epididymal specific). Injection of heterologous oPES (ovine PES) into male rats caused antibody production but failed to induce sterility, unlike results previously obtained when rat PES was injected into male rats. This suggests that only very restricted species-specific epitopes of PES might be useful for causing immunocontraception. Despite this, the sperm binding properties of PES purified from the rat (rat PES) and from the ram (oPES) were shown to be similar. When either rat PES or oPES, conjugated with a fluorescent probe (dimethylamino-fluorescein), was incubated with washed rat spermatozoa originating from the caput, corpus or cauda epididymis, results of flow cytometric analysis showed: (1) the number of spermatozoa bound to isologous or heterologous fluorescent PES, and (2) the binding-affinity of spermatozoa for PES was greater for sperm collected from more distal sites in the epididymis.

Animals↗

Effects of pivalic acid and sodium pivalate on L-carnitine concentrations in the cauda epididymidis and on male fertility in the hamster.

In this study, administration of pivalic acid or its sodium salt was found to decrease the L-carnitine concentration in the epididymal lumen of the hamster; it also tested whether this decrease affected sperm cell motility, chromatin structure, or fertilizing capacity. Provision of pivalic acid or its sodium salt (20 mM or 40 mM) in the drinking water of mature male golden hamsters for 30 days reduced (by 72%, 75%, and 83% in three experiments) the L-carnitine concentration of the cauda epididymidis but did not inhibit sperm chromatin condensation, as assessed by flow cytometry. The treatments did not alter the location of motile sperm in the epididymidis nor did they appreciably affect the motility of sperm obtained from the distal cauda epididymidis. The numbers and percentage of ova that reached the 2-cell stage 36-40 h after uterine insemination with spermatozoa from control and treated hamsters served as a measure of sperm fertility. Treatment with pivalic acid or sodium pivalate did not render male hamsters infertile although it appeared to reduce the fertilizing ability of their spermatozoa. These results suggest that the high concentration of L-carnitine present in the lumen of the cauda epididymidis is not required for maturation of sperm chromatin or development of sperm motility.

Animals↗

[Autoimmune asthenospermia induced by an epididymal protein, ovine prealbumin (oPES)].

The motility of ejaculated spermatozoa (% of progressive spermatozoa) has been evaluated visually on 26 adult rams. Half the animals were immunized with a secretory epididymal protein (prealbumin epididymal-specific (PES) ovine) injected according to immunizing protocols (Freund or Hunter adjuvant) intraperitoneally or intradermally (Freund or Hunter adjuvant) or intramuscularly (Hunter adjuvant or PES only). The other animals received the same product without the protein (controls). The product resulted in a strong asthenospermia which parallels the transient presence of anti-PES antibodies in the seminal plasma. A study with 64 ewes showed that the fertility of 10 immunized rams that had recovered sufficient forward motility to ensure fertilization, did not differ from that of control rams.

Animals↗

Purification of an ovine, androgen-dependent epididymal protein. Evidence for a strong amino acid sequence homology with serum albumin.

An ovine, testosterone-dependent protein was purified from an extract of epididymides of orchidectomized-, testosterone-implanted rams by ethylene glycol precipitation, anion exchange chromatography, preparative non-denaturing PAGE at alkaline pH and gel filtration. The protein which had previously been named ovine prealbumin-epididymis-specific protein (oPES), migrated as a single band ahead of ovine serum albumin (oSA). A single component, with an apparent MW of 60 kDa, lower than that of oSA, was also observed in SDS-PAGE. oPES was cleaved after lysyl residues using endoproteinase Lys-C and the hydrolysate was fractionated in 2 steps by reverse-phase HPLC. Six oligopeptides were recovered and sequenced. They all displayed complete identity with regions of bovine serum albumin scattered in the two-third N-terminal part. However, in 2 of them, there was no complete identity with homologous parts of oSA. This indicates that oPES and oSA are probably encoded by different genes.

Amino Acid Sequence↗

[Localization, on the head of ram spermatozoa, of affinity sites for the 64kD androgen dependent epididymal prealbumin].

The epididymis of the ram synthesizes under androgenic control of specific 64 kD protein. The purified protein appeared as a single band in SDS polyacrylamide gel electrophoresis. It was labelled and an antiserum was prepared in mice. Results showed localization of receptors sites for 64 kD on the periacrosomal plasma membrane of testicular spermatozoa. The protein itself was found on the periacrosomal area of both epididymal and ejaculated spermatozoa.

Androgens↗

Identification of androgen-dependent proteins synthesized in vitro by the ram epididymis.

Protein synthesis has been investigated in different regions of the epididymis from normal rams, castrate rams, and castrate testosterone supplemented rams. Results show that there are few differences in the pattern of [35S]methionine-labelled proteins synthesized in different regions of the normal epididymis despite the variation in the morphology of the epithelial cells lining the duct. Three androgen-dependent proteins of molecular weights 24000, 64000 and approximately 200 000 were identified. Testosterone did not stimulate protein synthesis in the proximal caput epididymidis (region 1-3), suggesting that testicular fluid is important in maintaining the activity of epididymal cells in this area.

Androgens↗

[Evidence for testosterone induced prealbumin secretion in ram epididymis].

The fluids of the Rete Testis and of the different areas of the epididymis (caput, corpus, cauda) were collected by micropuncture of the Rete Testis or the epididymal duct from caput and corpus of normal Rams (n = 3) and 4 months orchidectomized Rams having in the last month a subcutaneous implant testosterone (200 mg) which delivered a constant rate of testosterone for 4 weeks. Homogenates of epididymal tissues from orchidectomized Rams (3 months) were prepared in saline (n = 4). All samples diluted in saline, were centrifuged and submitted to polyacrylamide slab gel electrophoresis (7.5% acrylamide) at pH 8.3. Results showed an alpha-globulin Rf 1.1 whose molecular weight was approximately 105,000 D which was clearly detected into the fluid of the caput or corpus epididymis, weakly in the cauda epididymis of normal Rams and at the 3 levels of the epididymis of the testosterone supplemented castrates; it was absent in tissues of castrated Rams not supplemented with testosterone supplemented castrates; it was absent in tissues of castrated Rams not supplemented with testosterone. Results were discussed according to epididymal sperm maturation.

Animals↗

[The first cleavage of tubal sheep eggs after fertilization with epididymal or ejaculated spermatozoa].

Prealpes ewes (N = 40) were inseminated with mature (ejaculated or epididymal cauda) or immature (epididymal corpus) spermatozoa deposited in the uterine cavity at the time of an induced ovulation (61 hrs. after PMSG injection). Intratubal eggs, recovered and examined either 38 or 48 hrs. later, showed significant differences in segmentation depending on the degree of epididymal maturation of the spermatozoa. Proportion cleaved: 85% of eggs were cleaved after insemination with mature spermatozoa and only 30% after immature spermatozoa were used. Stage of cleavage: 48 hrs. after insemination with mature spermatozoa, 87% eggs were beyond the 4-cell stage, versus 0% after immature spermatozoa.

Animals↗

Decreased fertility and motility of spermatozoa from rats immunized with a prealbumin epididymal-specific glycoprotein.

This study investigated the effects on the progressive motility, zona-binding capacity, and fertility of spermatozoa from the cauda epididymidis of adult male rats that were actively immunized against an acidic glycoprotein secreted by the epididymis. The percentage of motile spermatozoa was less than 5% in nine of ten rats that received the epididymal antigen, and 40 to 50% in eight of the 10 control rats. In animals immunized against the antigen, there was a dramatic decrease, but not a complete suppression, in the capacity of epididymal spermatozoa to bind the zona pellucida as compared with the nonimmunized controls. Fertility was decreased two weeks after the end of the treatment, but partial restoration of fertility was observed 6 months later.

Androgen-Binding Protein↗

Binding of epididymal proteins to the spermatozoa of ram.

Glycoproteins and proteins, extracted from the corpus epididymides of rams and linked to colloidal gold, bind specifically onto the plasma membrane of spermatozoa. The sites for the glycoproteins are saturated on spermatozoa after the passage through the corpus epididymidis. Sites for proteins are present at the anterior part of testicular spermatozoa, the whole plasma membrane of the head of spermatozoa from the corpus epididymidis and the posterior part of the head, excluding the equatorial segment, of most spermatozoa from the cauda epididymidis. The technique used is simple, rapid and reliable.

Animals↗