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L J Zaneveld

Publications and source records attributed to L J Zaneveld.

At least 55 records · Page 3Linked to original sources
PubMed1989

Ethanol-induced delayed male puberty in mice is not due to impaired Leydig cell function.

The present study was performed to evaluate the involvement of reduced testosterone in ethanol-induced impairment of male reproductive tract development. In vivo and in vitro gonadotropin (hCG)-stimulated steroidogenesis were examined in CFW mice as a function of chronic ethanol treatment during pubertal development. Chronic ethanol treatment from ages 20 to 49 days impaired testicular growth from ages 35 days (29 +/- 2 mg vs 37 +/- 2 mg for pair-fed controls) to 50 days (42 +/- 2 mg vs 63 +/- 2 mg for pair-fed controls). Consistent with a reduction in testicular weight, testicular content of androstenedione, testosterone, and dihydrotestosterone (DHT) was depressed in ethanol-treated mice. At age 50 days, the content (expressed as pg/testis) of androstenedione, testosterone, and DHT was reduced in ethanol-treated animals by 49%, 31%, and 38%, respectively, as compared to that of their respective controls. However, no difference in plasma (ng/mL) or testicular (pg/mg protein) concentrations of steroids was observed. Except for the DHT response at ages 35 to 40 days, neither in vivo nor in vitro steroidogenesis was impaired by chronic ethanol treatment at ages 26 to 50 days; similarly, the acute ethanol effect on steroidogenesis was unaffected. However, an adaptive increase (54%-173%) in the in vivo testosterone response to hCG was seen at ages 26 to 40 days. The data indicate that 1) chronic ethanol treatment does not impair gonadotropin-stimulated steroidogenesis or result in tolerance to acute ethanol effects on steroidogenesis in older animals; and 2) ethanol-induced reduction in testosterone is not a likely mechanism for delayed sexual maturation.

Aging↗
PubMed1989

Treatment of human spermatozoa with an egg yolk medium can enhance the outcome of in vitro fertilization.

In at least 4 of 7 cases, fertilization of intact human oocytes was more successful when spermatozoa were pretreated with TEST yolk medium at 5 degrees C for 2 hours as compared with the standard treatment with Ham's F-10 only. Both pregnancies that were obtained after the transfer of the fertilized oocytes resulted from oocytes fertilized by TEST yolk-treated spermatozoa. No decrease in fertilization occurred in any of the cases after TEST yolk treatment. If these results hold true for a larger series of patients, it may be worthwhile for the standard IVF incubation system of spermatozoa to include TEST yolk.

Culture Media↗
PubMed1989

Human sperm selection by glass wool filtration and two-layer, discontinuous Percoll gradient centrifugation.

Glass wool filtration and two-layer, discontinuous Percoll (Pharmacia, Uppsala, Sweden) density gradient centrifugation resulted in an average recovery of 50% to 70% of the progressively motile and about 50% of the hypoosmotic swelling (HOS)-positive spermatozoa. Glass wool filtration tended to be more successful than Percoll centrifugation when the ejaculates were asthenozoospermic or produced a suspect/abnormal HOS test. After selection, the acrosin activity increased approximately two- to threefold, but no significant improvement in the percentage of normal sperm forms occurred. Experiments with mixtures of untreated and frozen-thawed ejaculates confirmed that glass wool filtration is more effective in removing nonmotile and HOS-negative spermatozoa than the two-layer Percoll centrifugation technique when the percentage of these types of spermatozoa in the ejaculate is high. The simplicity of these techniques and the good recovery of apparently viable spermatozoa makes these methods more desirable than other, more complicated techniques or procedures that yield a lower recovery of motile spermatozoa.

Cell Separation↗
PubMed1989

Semen quality and in-vitro fertilization.

The standard sperm parameters, and a newly developed assay, the hypoosmotic swelling (HOS) test, of 208 ejaculates were correlated with in vitro fertilization (IVF) outcome to assess their predictive value of the fertilizing capacity of spermatozoa. One hundred fifty-three (73.6%) of the ejaculates possessed spermatozoa that fertilized at least one oocyte and were considered fertile. Among the semen parameters studied, only the HOS test had a relatively high (r = 0.46, p less than 0.001) association with the fertilizing capacity of the spermatozoa. This test was also able to predict the outcome of IVF more reliably than the other semen parameters studied.

Female↗
PubMed1989

Nonhormonal mediation of male reproductive tract damage: data from contraceptive drug research.

Chemicals can interfere with hormonal control of the male reproductive tract and/or directly alter male reproductive tract function. A review is presented of those chemicals developed and tested as male contraceptive agents which have a direct effect on the male reproductive tract with minimal disturbance of the hormonal milieu. Such chemicals can have one or more sites of action: 1) the testis, disturbing spermatogenesis; 2) the epididymis, altering sperm maturation; 3) the vas deferens, affecting sperm transport; and 4) the accessory sex glands, entering the ejaculate and changing the functional activity of the spermatozoa. Examples of each mode of action are presented.

Animals↗
PubMed1988

Wheat germ agglutinin treatment of follicle cell-free mouse oocytes inhibits fertilization.

Controversy exists whether treatment of follicle cell-free oocytes with wheat germ agglutinin (WGA) prevents fertilization. Lack of inhibition in one case has led to the suggestion that acrosin may not be a zona lysin. To re-examine the effect of the WGA, the zona pellucida of follicle cell-free mouse oocytes was made more resistant to proteinase digestion by treatment with 10 or 50 micrograms/ml WGA. Such WGA-treated oocytes showed decreased fertilizability when washed to remove excess WGA and incubated with capacitated spermatozoa. Oocyte cleavage was used as an end point, because a large number of spermatozoa adhered to the eggs after WGA treatment, making observation of sperm penetration and pronucleus formation unreliable. Resistance to proteinase digestion increased, and the fertilizability decreased with the higher amount of WGA. The action of WGA was most likely not mediated by a direct effect on sperm motility, sperm acrosin activity, sperm binding to the zona pellucida, or oocyte cleavage. WGA did not affect the acrosome reaction of guinea pig spermatozoa. These data show that WGA treatment of follicle cell-free mouse oocytes results in decreased fertilizability, possibly by rendering the zona pellucida more resistant to sperm proteinase digestion.

Acrosin↗
PubMed1988

Development of the polyurethane sponge as a delivery system for aryl 4-guanidinobenzoates.

The Today Contraceptive Sponge was evaluated as a vehicle for the delivery of aryl 4-guanidinobenzoates (AGs) which are highly active sperm acrosin inhibitors. Studies in animals have shown that several AGs are more potent vaginal contraceptives and less irritating to the vagina than nonoxynol-9 (N-9), the most frequently used active ingredient in commercial vaginal contraceptive formulations. Neither nonoxynol-9 nor the material that could be solubilized from the sponge matrix altered the enzyme-inhibitory activity of 4'-acetamidophenyl 4-guanidinobenzoate HCl (AGB), 4'-carboxyphenyl 4-guanidinobenzoate HCl (EGB) or 4'-carbomethoxyphenyl 4-guanidinobenzoate HCl (MSGB). Besides being acrosin inhibitors, all three AGs exhibited antimotility activity towards human spermatozoa, EGB being as potent as N-9. The antimotility effects of the AGs and N-9 were additive. For subsequent studies, AGB was used as the model compound. Manufacture of the AGB-containing sponges did not affect the chemical structure of AGB. Good release rates of AGB were obtained from the sponges over a 7-day period. The release rates were 20-50% higher when the sponges also contained N-9. These results indicate that certain AGs exert a dual contraceptive action on spermatozoa by inhibiting both the sperm enzyme acrosin and sperm motility. Furthermore, the polyurethane sponge appears to be a convenient and satisfactory long-term delivery system for the AGs. A mixture of N-9 and AG can be used clinically because these compounds have no adverse effects on each other.

Benzoates↗
PubMed1988

Development of a polymeric releasing device for 2'-carbomethoxyphenyl 4-guanidinobenzoate (a proteinase inhibitor): release rate, in vitro antifibrinolytic activity and in utero contraceptive effect.

A polymeric delivery system consisting of ethylene-vinyl acetate copolymer (EVAc) was developed for 2'-carbomethoxyphenyl 4-guanidinobenzoate (MSGB), a potent inhibitor of the sperm enzyme acrosin. The optimal device consists of copolymer with 40% vinyl acetate by weight (EVAc/40), 65% drug loading and MSGB with a particle size of 250-499 micron. This formulation yields a device that is highly flexible and can be shaped to many forms and sizes. Construction of the device does not alter the properties of MSGB. Well controlled release of MSGB from the device occurs in vitro and in the uteri of rats. The in vitro release rate under "infinite sink" conditions is essentially the same as the in vivo release rate. The contraceptive effect of the MSGB-releasing device was tested in rabbits by placing a blank (control) device in one uterine horn and an MSGB-releasing device in the contralateral horn. In contrast to blank devices, MSGB-releasing devices completely prevent pregnancy, not only by inhibiting fertilization but also by decreasing implantation. MSGB possesses high in vitro antifibrinolytic activity. These results indicate that a very flexible device can be constructed for uterine application which retains its contraceptive effect by release of MSGB. The antifibrinolytic activity of MSGB may further decrease the menorrhagia that can be associated with IUD use.

Animals↗
PubMed1988

Development of a potentially reversible vas deferens occlusion device and evaluation in primates.

A vas deferens occlusion device has been developed and tested in primates. The device consists of two silicone plugs held together by a nylon suture. Implantation of each plug is readily accomplished by making two small puncture holes in the vas deferens and inserting one plug into the lumen toward the epididymis and the other plug toward the seminal vesicles. Implantation is aided by a metal stylus inserted in each plug to give the plug rigidity. The stylus is removed after insertion of the plug into the vas deferens. Two separate primate experiments showed that the device completely prevents sperm transport over a 7-month period. Upon device removal, all of the primates ejaculated spermatozoa again at normal concentrations and motility. These results indicate the potential contraceptive use of the device and encourage its validation in men.

Humans↗
PubMed1988

Induction of the human sperm acrosome reaction by human oocytes.

The acrosome reaction of human spermatozoa incubated in the presence or absence of vested human oocytes was investigated. All gametes were obtained from human in vitro fertilization (IVF) cases. Spermatozoa were collected after incubation in insemination medium only and following removal of the oocytes from insemination medium during the IVF procedure. After 16 hours of incubation 18.5% of the spermatozoa in insemination medium alone were acrosome-reacted compared to 31.5% for spermatozoa incubated in medium containing oocytes. The acrosome reaction of spermatozoa incubated with fertilized or unfertilized oocytes was also investigated. The percentage of acrosome reaction did not differ (P greater than 0.05) between the two groups (29.7% in the fertilized cases versus 30.7% in the unfertilized cases). Completion of oocyte nuclear maturation did not affect the proportion of acrosome-reacted spermatozoa observed with unfertilized eggs. A similar (P greater than 0.05) percentage of acrosome reacted spermatozoa were observed regardless of whether the unfertilized oocytes had (29%) or had not (35%) reached metaphase II. These findings indicate the acrosome reaction of human spermatozoa is enhanced in the presence of vested human oocytes. Furthermore, there is no apparent correlation between the percentage of the population of spermatozoa that acrosome react in the medium and the potential of an oocyte for fertilization.

Acrosome↗
PubMed1987

Delayed pubertal development of the male reproductive tract associated with chronic ethanol ingestion.

Little is known concerning the sensitivity of the reproductive tract to ethanol as a function of development. The present study was conducted to evaluate the action of chronic ethanol ingestion on sexual maturation of the male. Mice were given free access to liquid diets containing 5% (v/v) ethanol for either 29 or 43 days, starting at age 20 days. Controls were given liquid diets in which isocaloric sucrose replaced the ethanol. Daily diet consumption and peak blood ethanol levels were highest during the first 2 weeks of treatment, dropping thereafter to adult levels of approximately 680 ml/kg body weight and 160 mg/dl respectively. Plasma testosterone levels were depressed by ethanol throughout treatment, the reduction being somewhat greater when measured during week 6 of treatment (average = 74% inhibition) as compared to either week 2 (36%) or week 4 (25%). Average weights of testes, epididymides and seminal vesicles were depressed by 24% (P less than 0.002), 16% (P less than 0.005) and 13% (NS), respectively, after 29 days. Testicular development was also impaired in ethanol-treated animals after 29 days. Tunica albuginea thickness and seminiferous tubule diameter were decreased (by 31%, P less than 0.05; and 16%, P less than 0.01 respectively), whereas desquamation of immature germ cells and inactive tubules were increased (325 and 780% respectively; P less than 0.01). Quality of spermatogenesis was poorer in ethanol-treated animals (P less than 0.05). Also observed were decreased sperm motility (62% inhibition, P less than 0.01) and capacity to fertilize (decreased by 67%, P less than 0.01), and an increase in the incidence of morphologically abnormal spermatozoa (by 163%, P less than 0.001). Semen volume was lower (reduced by 57%, P = 0.05), as was the total number of motile ejaculated spermatozoa (reduced by 81%, P less than 0.05). After 43 days treatment, improvement was noted in all indices of fertility except for the number of motile ejaculated spermatozoa. Significant differences persisted only for dysmorphic spermatozoa and volume and sperm count of electroejaculated semen. These data suggest that ethanol ingestion during pubertal development can delay several aspects of sexual maturation in the male.

Animals↗
PubMed1987

Characterization of human sperm plasma membrane: glycolipids and polypeptides.

The plasma membranes from ejaculated human spermatozoa were removed by nitrogen cavitation (600 PSI for 10 min) and isolated by centrifugation followed by a discontinuous sucrose density gradient centrifugation. Glycolipid analysis of the plasma membrane revealed a three-fold enrichment in gangliosides: GM3 and GD1a/GD1b and neutral glycolipids: globoside and sulfatide as compared to that of whole human sperm. Two dimensional electrophoresis of human sperm plasma membranes revealed about 75 polypeptides. Several of these polypeptides were similar in migration and in display of shape and color to that found in boar sperm plasma membranes.

Cell Membrane↗
PubMed1987

Acrosomal enzymes and ultrastructure of unfrozen and cryotreated human spermatozoa.

Pooled semen judged to be normal in all parameters was divided into a number of aliquots which were either 1) kept untreated; 2) mixed with glycerol (10% v/v); 3) washed by centrifugation and resuspended to the original volume with buffer; or 4) washed and resuspended in buffer with glycerol (10% v/v). The progressive motility, viability, ultrastructure, and acrosomal enzyme activity (8 different hydrolases) were studied before and after cryotreatment. The described washing procedure effectively removed seminal plasma, and did not alter sperm motility, sperm viability, sperm ultrastructure, or the acrosomal enzymes studied. Glycerol (10%, v/v) had a deleterious effect on most parameters evaluated before cryotreatment. Cryotreatment severely altered the motility and viability of the spermatozoa and their acrosomal morphology but did not cause significant decreases in most of the acrosomal hydrolases measured. However, acrosin/proacrosin levels decreased by 50-80% and were correlated to the acrosomal damage. A simple assay for the measurement of acrosin/proacrosin enzyme levels in whole sperm is presented which could be used as a monitor for acrosomal integrity. No significant differences were seen between the samples cryotreated in the absence or presence of seminal plasma.

Acid Phosphatase↗
PubMed1987

Purification and partial chemical characterization of a glycoprotein with antifertility activity from human seminal plasma.

The preparation of a highly purified antifertility factor from human seminal plasma is described, and some of its biochemical properties have been determined. Purification was achieved by ultracentrifugation of particle-free human seminal plasma, followed by chromatography of the precipitate using carboxymethyl cellulose, concanavalin A, and Sepharose 6B columns. An occasional contaminant was further removed by preparative isoelectric focusing. During the purification procedures, the activity of the fractions was monitored by mixing them with capacitated mouse spermatozoa for 20 min before adding an aliquot to intact mouse oocytes, and determining fertilization after 24 h. The I50 (amount causing a 50% reduction in fertilization as compared to the control) of the final purified factor was 45 micrograms protein. Purity was established by standard and sodium dodecyl sulfate disc gel electrophoresis, isoelectric focusing, high-pressure liquid chromatography, and sedimentation analysis. These methods, as well as Sepharose gel filtration, were also used for the molecular weight estimations; good agreement was obtained between the various techniques. The factor appears to be a glycoprotein with a molecular weight of about 200,000. It consists of two subunits with molecular weights of about 125,000 and 72,000 and s-20,w of 6.2 s and 4.3 s. The factor contains relatively high amounts of aspartic acid and glutamic acid residues as well as leucine and serine, but only small amounts of tryptophan and no methionine was detected. The carbohydrate fraction is particularly rich in galactose and N-acetylgalactosamine but also contains mannose and N-acetylglucosamine and small amounts of fucose and sialic acid.

Amino Acids↗
PubMed1987

Effect of aryl 4-guanidinobenzoates on the acrosin activity of human spermatozoa.

Certain aryl 4-guanidinobenzoates (AGs; inhibitors of proteinases, including the sperm enzyme acrosin) have been shown to be more potent vaginal contraceptives in rabbits and less toxic than nonoxynol-9, the active ingredient of most marketed vaginal contraceptive formulations. To determine if these AGs can contact sperm and inhibit acrosin when mixed with the entire human ejaculate for a short period of time (roughly imitating clinical conditions), the inhibitors were added to semen at various concentrations for 2 min, after which the seminal plasma and unbound inhibitor were removed from the sperm by Ficoll centrifugation. Subsequently, the total arginine amidolytic activity of the spermatozoa was determined spectrophotometrically after a combined treatment that resulted in extraction, proacrosin activation, and reaction with substrate. Dose-response curves were prepared. All AGs studied were effective inhibitors of the amidolytic activity under these conditions, with ED50 values (the dose levels at which half of the acrosin associated with 10(6) sperm is inhibited) ranging from 10(-5) to 10(-7) M. To determine the effect on the proteolytic activity of individual spermatozoa, the experiment was repeated with 4'-acetamidophenyl 4-guanidinobenzoate (AGB), and the protease released from the sperm was measured by the gelatin-plate assay. The inhibition results were similar to those obtained by extraction of the spermatozoa and measurement of amidolytic activity. Thus, when mixed with the human ejaculate, AGs interact rapidly with spermatozoa to inhibit both their arginine amidolytic and proteolytic activity (probably due primarily or only to inhibition of acrosin) and remain bound even after removal of the seminal plasma. These data encourage further study of the compounds for contraceptive purposes.

Acrosin↗
PubMed1986

Isolation and partial characterization of the plasma membrane from human spermatozoa.

Ejaculated human spermatozoa were subjected to nitrogen cavitation (600 psi for ten min) to remove the plasma membrane (PM). Electron microscopic examination of the cavitated cells revealed that 33% of the PM was removed from the sperm which includes both the head and tail regions. The released membrane was separated from the cavitated cells by centrifugation followed by a discontinuous sucrose density gradient centrifugation. A single membrane population was resolved at the 1.0 M sucrose interface. Examination of the isolated membranes by electron microscopy revealed vesicles of various sizes displaying unit membrane structures. Biochemical analysis of the isolated membranes showed a threefold enrichment in the surface membrane marker 5' nucleotidase and also suggested little contamination by enzymes from the cytosol (lactate dehydrogenase) or mitochondria (cytochrome oxidase). Analytical lipid analysis of the isolated membranes revealed a 26-fold enrichment in the distribution of cholesterol, an 11-fold enrichment of phospholipids, and a cholesterol:phospholipid molar ratio of 0.83. Also found was a twofold increase in glycosphingolipids which are ubiquitous components of PM in eukaryotic cells. These data indicate that the membrane vesicles isolated after nitrogen cavitation are primarily PM.

5'-Nucleotidase↗
PubMed1986

Comparison of the spermicidal activity and acute toxicity of nonoxynol-9 and agent 741 [alkylphenoxy polyethoxy ethanol(10)].

A spermicidal agent called "741" is used in the People's Republic of China as a substitute for nonoxynol-9 in vaginal contraceptive preparations. The relative spermicidal activity of these two agents was evaluated using dog, rabbit, monkey and human semen. Acute LD50 determinations in mice were also performed. The spermicidal activity and acute toxicity of both agents were either identical or very similar in all species. Since agent 741 is less expensive than nonoxynol-9 to manufacture and equally as potent in vitro, it is an alternative spermicide for vaginal contraceptive formulations.

Animals↗