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Results for “Fertility Agents”

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At least 19 recordsLinked to original sources
PubMed1993

Eliminating the risk of life-endangering complications following overstimulation with menotropin fertility agents: a report on women undergoing in vitro fertilization and embryo transfer.

OBJECTIVE: To evaluate a new method for preventing the life-endangering complications associated with inadvertent menotropin-induced severe ovarian hyperstimulation in patients undergoing in vitro fertilization and embryo transfer (IVF-ET). METHODS: Seventeen women each underwent a single cycle of controlled ovarian hyperstimulation with menotropins in preparation for IVF-ET. The indications for IVF-ET were tubal occlusion in nine, endometriosis in six, and unexplained infertility in two. The peak plasma estradiol (E2) concentration before hCG administration was greater than 6000 pg/mL and more than 30 ovarian follicles were detected by transvaginal ultrasound. Thus, life-endangering complications associated with severe ovarian hyperstimulation syndrome were highly likely to occur following hCG administration. Rather than cancel the cycle of treatment, menotropin therapy was discontinued and hCG administration was deferred for a number of days until the plasma E2 concentration fell below 3000 pg/mL ("prolonged coasting"), whereupon hCG was administered and egg retrievals and ETs were duly performed. RESULTS: None of the women developed severe ovarian hyperstimulation syndrome. There were six viable pregnancies (35.2%), which proceeded normally. CONCLUSION: This study indicates that "prolonged coasting" prevents severe ovarian hyperstimulation syndrome in severely overstimulated women undergoing IVF-ET, without necessitating cycle cancellation.

Adult↗
PubMed1981

Influence of metabolism on the activity of a new anti-fertility agent, 2-(3-ethoxyphenyl)-5,6-dihydro-s-triazolo [5,1-a]isoquinoline (DL 204-IT), in the rat and the hamster.

The activity of a new non-hormonal anti-fertility agent, 2-(3-ethoxyphenyl)-5,6-dihydro-s-triazolo[5,1-a]isoquinoline (DL 204-IT), effective in terminating pregnancy after i.m. or s.c. treatment, was tested after single and multiple oral doses given to rats and hamsters. Although the compound was absorbed well from the gastrointestinal tract and the plasma levels of the radioactivity administered were rather high and sustained, the oral activity was by two orders of magnitude lower than the parenteral one. The plasma profile of the metabolites found after both p.o. and i.m. administration indicates that the compound is rapidly metabolized. Seven metabolites (I-VII) were isolated from the urine of pregnant rats and fully characterized by MS, IR and NMR spectroscopy. They are 2-(3-hydroxyphenyl)-5,6-dihydro-s-triazolo[5,1-a]isoquinoline (I); 2-(3,4-dihydroxyphenyl)-5,6-dihydro-s-triazolo[5,1-1]isoquinoline (II); 2-(3-hydroxyphenyl)-5,6-dihydro-6 beta-hydroxy-s-triazolo[5,1-a]isoquinoline (III); metabolite I-sulphate ester (IV); metabolite III-3-sulphate ester (V); metabolite I-beta-D-glucuronide (VI) and metabolite II-3-beta-D-glucuronide (VII). Metabolite I was shown to be from 1/10 (rat) to 1/30 (hamster) as active as the parent compound, while metabolites II and III were completely inactive. The very low oral activity of DL 204-IT seems to be due mainly to its rapid biotransformation.

Administration, Oral↗
PubMed1996

Inhibition of sperm-zona binding by suramin, a potential 'lead' compound for design of new anti-fertility agents.

Progress in developing new contraceptive agents, particularly for the male, is extremely slow. Here, we report on a novel property of the anti-trypanosomal drug suramin: the ability to act at the sperm-egg interface and prevent fertilization. Suramin is a polysulphonated compound that inhibits binding of capacitated mouse spermatozoa to the zona pellucida in vitro with an IC50 of 12.4 microM. The drug is only effective at the time of fertilization and is not inhibitory if gametes are pre-treated separately. Autoradiographic localization of suramin binding sites on mouse, boar and human spermatozoa shows that they are intracellular, principally in the head region. The sperm protein recognized by suramin has been identified as proacrosin which is known to interact with sulphate groups on zona glycoproteins. Zona pellucida glycoproteins do not bind suramin, suggesting that the drug blocks the ability of proacrosin/acrosin, exposed during the acrosome reaction, to mediate the secondary binding phase of spermatozoa to the zona during fertilization. Structure-based design studies have the potential to generate safe suramin mimetics that would form the basis for a new generation of non-steroidal contraceptive agents.

Acrosin↗
PubMed1980

Pregnancy terminating activity of a new non-hormonal anti-fertility agent, 2-(3-ethoxy-phenyl)-5,6-dihydro-s-triazole [5,1-a] isoquinoline (DL 204-IT) in the rat and the hamster. Studies on the factors affecting its activity.

The biological and the pharmacokinetic profiles of 2-(3-ethoxy-phenyl)-5,6-dihydro-s-triazole [5,1-a]isoquinoline (DL 204-IT) were explored in rats and hamsters at different stages of gestation (1st--11th day) after single and multiple (5 days) doses given in different vehicles (oily and aqueous) and by different routes of administration (s.c., i.m., i.v.). The effectiveness of the compound was demonstrated to be dependent on time of gestation, dose and vehicle. DL 204-IT did not show any pre-implantation activity. The optimal time for treatment was found to be immediately after the implantation of blastocysts. Time-course studies demonstrated that the anti-fertility action is slow and progressive with subsequent degeneration and reabsorption (rats and hamsters), or expulsion (only hamsters) of conceptuses. The biological and pharmacokinetic data show that with prolonged presence of the compound at the site of action (the utero-placental complex) lower doses are far more active in interrupting embryonal development than are much higher ones for shorter time periods.

Abortifacient Agents↗
PubMed1981

Inhibition of superovulation and alteration of ova transportation in hamsters by prostaglandin and DL-204-IT, an anti-fertility agent.

The compound 2(3-ethoxyphenyl)-5, 6-dihydro-s-triazole- [5, 1-2] isoquinoline (DL-204-IT or L-11204) inhibited PMS-induced superovulation and reduced the number of recoverable ova in the oviducts of hamsters. PGE2 non-significantly reduced the number of ova shed but significantly decreased the number of oviductal ova. DL-204-IT was more potent than PGE2 for these effects. Administration of both compounds resulted in a complete block of ovulation. Inhibition of prostaglandin metabolism by DL-204-IT may be the cause for these effects, but no direct evidence is presently available.

Animals↗
PubMed1978

Mode of action of alpha-chlorohydrin as a male anti-fertility agent. Inhibition of the metabolism of ram spermatozoa by alpha-chlorohydrin and location of block in glycolysis.

1. The effect of alpha-chlorohydrin on the metabolism of glycolytic and tricarboxylate-cycle substrates by ram spermatozoa was investigated. The utilization and oxidation of fructose and triose phosphate were much more sensitive to inhibition by alpha-chlorohydrin (0.1-1.0mm) than lactate or pyruvate. Inhibition of glycolysis by alpha-chlorohydrin is concluded to be between triose phosphate and pyruvate formation. Oxidation of glycerol was not as severely inhibited as that of the triose phosphate. This unexpected finding can be explained in terms of competition between glycerol and alpha-chlorohydrin. A second, much less sensitive site, of alpha-chlorohydrin inhibition appears to be associated with production of acetyl-CoA from exogenous and endogenous fatty acids. 2. Measurement of the glycolytic intermediates after incubation of spermatozoal suspensions with 15mm-fructose in the presence of 3mm-alpha-chlorohydrin showed a ;block' in the conversion of glyceraldehyde 3-phosphate into 3-phosphoglycerate. alpha-Chlorohydrin also caused conversion of most of the ATP in spermatozoa into AMP. After incubation with 3mm-alpha-chlorohydrin, glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase activities were decreased by approx. 90% and 80% respectively, and in some experiments aldolase was also inhibited. Other glycolytic enzymes were not affected by a low concentration (0.3mm) of alpha-chlorohydrin. Loss of motility of spermatozoa paralleled the decrease in glyceraldehyde 3-phosphate dehydrogenase activity. alpha-Chlorohydrin, however, did not inhibit glyceraldehyde 3-phosphate dehydrogenase or triose phosphate isomerase in sonicated enzyme preparations when added to the assay cuvette. 3. Measurement of intermediates and glycolytic enzymes in ejaculated spermatozoa before, during and after injection of rams with alpha-chlorohydrin (25mg/kg body wt.) confirmed a severe block in glycolysis in vivo at the site of triose phosphate conversion into 3-phosphoglycerate within 24h of the first injection. Glyceraldehyde 3-phosphate dehydrogenase activity was no longer detectable and both aldolase and triose phosphate isomerase were severely inhibited. Spermatozoal ATP decreased by 92% at this time, being quantitatively converted into AMP. At 1 month after injection of alpha-chlorohydrin glycolytic intermediate concentrations returned to normal in the spermatozoa but ATP was still only 38% of the pre-injection concentration. Motility of spermatozoa was, however, as good as during the pre-injection period. The activity of the inhibited enzymes also returned to normal during the recovery period and 26 days after injection were close to pre-injection values. 4. An unknown metabolic product of alpha-chlorohydrin is suggested to inhibit glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase of spermatozoa. This results in a lower ATP content, motility and fertility of the spermatozoa. Glycidol was shown not to be an active intermediate of alpha-chlorohydrin in vitro.

Animals↗
PubMed1991

Presence of a 16 kd protein in human seminal plasma counteracts the effects of the anti-fertility agent, gossypol.

Gossypol inhibited lactate dehydrogenase (LDH) noncompetitively in human spermatozoa. The inhibitory effect of gossypol on LDH was cancelled by the addition of human serum albumin, human gamma-globulin, bovine serum albumin or human seminal plasma. Seminal plasma was at least 10 times more effective than the other three proteins, when expressed on a per mg protein basis. Attempts were made to purify the active fraction from human seminal plasma. The purification steps included gel filtration, ammonium sulphate precipitation, centrifugal microconcentration and fast-performance liquid chromatography. A single active protein of Mr = 16,000 was purified to a final yield of 0.18%. The 16 kd protein was not observed in male blood plasma. The protein was found to be heat-stable and leucine-rich (16% of the molecule), and has been designated 'gossact'. The inhibitory effect of gossypol on the LDH reaction was completely blocked by the addition of gossact (5 micrograms/ml); human blood plasma (25 micrograms/ml) and human serum albumin (200 micrograms/ml) were far less potent in this assay. In addition, gossact bound 1.4 mol of gossypol/mol of protein with the dissociation constant (Kd) = 3.06 x 10(-5) M. The role of gossact in the protection of LDH from gossypol is discussed.

Binding, Competitive↗
PubMed1980

Short term metabolic effects of the anti-fertility agent, gossypol, on various reproductive organs of male mice.

In order to evaluate the short term metabolic effects of gossypol on the testes as well as any possible effects on the secondary sex organs, Balb C mice were injected subcutaneously with various doses of gossypol (0.25-25.0 mg/kg body weight) in corn oil for 10 days. Wet weights of several different secondary sex reproductive organs decreased during gossypol treatment. However, wet weights of the testes during treatment remained equal to or greater than control values. Following 10 days of gossypol treatment, incorporation of [3H]thymidine or [3H]amino acids into trichloroacetic acid precipitable macromolecules was inhibited in the seminal vesicles and ventral prostates normalized to either DNA or wet weight. Treatment with gossypol also had an inhibitory effect on epididymal sperm count at the two highest doses. These results demonstrate that gossypol will decrease sperm count at high dose levels after treatment of male mice for as short as 10 days. However, its overall effects are not limited to the testes and spermatogenesis but, in addition, it has dramatic inhibitory effects on protein and nuclei acid metabolism in the secondary sex organs.

Animals↗
PubMed1997

Menstrual bleeding patterns in untreated women. Task Force on Long-Acting Systemic Agents for Fertility Regulation.

Menstrual histories recorded by more than 1000 healthy, untreated women have been analyzed using the reference period method. Results were obtained for each year of age from 15 to 49. Between menarche and age 19, the most important feature of menstrual patterns is their variability. Within-woman mean segment (cycle) length then decreases slowly but steadily, from 29.0 days at age 20 to 26. 7 days at age 40. The range of segment lengths over a year also falls, to a minimum of 7 days at age 38. During the 40s, mean segment length rises to 29 days at age 49, and there is a sharp increase in the range, to 28 days. The length and variability of bleeding episodes, however, changes little between the ages of 19 and 49. Modifications to the World Health Organization definitions of 'clinically important' bleeding patterns are proposed.

Adolescent↗