Antide bioavailability: single dose administration for suppression of testosterone and inhibin in male monkeys.

The pharmacokinetics and pharmacodynamics of a single sc injection of Antide on testosterone (T) and inhibin secretion in intact male cynomolgus monkeys were examined. Fifteen primates were randomized to three groups receiving: propylene glycol and water vehicle, 3 mg/kg Antide, and 10 mg/kg of Antide. Antide at the 10 mg/kg dose caused long-term suppression of T ranging from 24-56 days. At the 3 mg/kg dose, suppression of T was of shorter duration. Serum Antide levels were significantly greater in the 10 mg/kg group than the 3 mg/kg group (p less than 0.02), both initially and through 35 days post-treatment. The duration of testosterone inhibition and sustained Antide levels were significantly correlated (p less than 0.01). Inhibin concentrations followed the same general pattern as testosterone reaching a nadir on day 21 post-treatment before subsequent recovery. The prolonged suppressive effect of Antide on T without detectable side effects makes this compound an excellent candidate for clinical evaluation.

Studies on the in vitro spermicidal activity of synthetic magainins.

Two synthetic magainins A and G are shown to have spermicidal activity. Transmission electron microscopic micrographs show that both magainins alter the plasma membranes of sperm and that these actions are rapid. Further studies will better delineate the contraceptive potential of synthetic magainins.

PIP: 2 synthetic magainins--A and G-- have been shown, through transmission electron microscopy, to have spermicidal activity. Magainins, a class of peptides isolated from the skin of the African clawed frog. I have been demonstrated to have wide spectrum in vitro antimicrobial activity. In this study, semen sample collected from 7 healthy volunteers were diluted with magainins A and G and then examined for spermiostatic activity. Sperm diluted only with saline were used as a control. Sperm assays indicated the potency of magainin A to be significantly greater than that of magainin G. Magainin A demonstrated spermiostatic activity at concentrations of 0.024-0.095 mg/mL compared to concentrations of 0.095-0.380 mg/mL for magainin G. A similar pattern was identified in the concentration of peptide required to inhibit sperm motility. Magainin A inhibited sperm motility when diluted in seminal plasma at concentrations of 0.77-1.54 mg/mL, while 1.54-3.08 mg/mL of magainin G were required to produce this effect. In the transmission electron microscopic studies, magainin-treated sperm cells incubated with either peptide consistently demonstrated denudation of the outer plasma membrane and partial disappearance of the acrosome, while sperm incubated in saline remained unaltered. It is hypothesized that magainins exert their spermicidal activity by disrupting the outer plasma membrane. The contraceptive potential of synthetic magainins should be explored through animal studies that measure the in vivo effects of seminal fluid and vaginal secretions on magainin activity and the effects of these agents on vaginal and cervical mucosa.

Progesterone levels on the day of human chorionic gonadotropin administration in cycles with gonadotropin-releasing hormone agonist suppression are not predictive of pregnancy outcome.

In in vitro fertilization (IVF) cycles using gonadotropin-releasing hormone agonist (GnRH-a) suppression, we investigated whether an elevated progesterone (P) level on the day of human chorionic gonadotropin (hCG) administration indicates premature luteinization and is associated with a lower pregnancy rate. We retrospectively studied 101 patients treated with the GnRH-a leuprolide acetate, begun in the luteal phase of the prior menstrual cycle and continued until the day of hCG administration. On the day of hCG, 72 patients had P less than 0.9 ng/mL and 29 had less than or equal to 0.9 ng/mL. Patients in the high P group had a significantly greater estradiol level on the day of hCG. No significant difference in clinical pregnancy rates or ongoing pregnancy rates occurred between the low P and high P groups. We conclude that in IVF cycles pretreated with GnRH-a, P levels on the day of hCG are not predictive of conceiving in that cycle.

The prevalence of human immunodeficiency virus in patients and their spouses entering a large in vitro fertilization program.

Between September 1987 and August 1989, all patients and their spouses entering our in vitro fertilization (IVF) program were screened for the human immunodeficiency virus (HIV) using the enzyme-linked immunosorbent assay (ELISA). Of 848 patients and 848 spouses tested, all but 4 patients and 1 husband tested negative. Of those who tested positive on repeat testing with ELISA, only one was positive on Western blotting (HIV prevalence, 0.59 per 1000). During this same time period 1187 samples of human cord blood were used to make tissue culture medium for the IVF embryology laboratory. One sample was discarded because of positive HIV on ELISA and Western blotting; two other samples were discarded because of positivity to the hepatitis B surface antigen. While we believe that routine HIV screening of IVF patients and their spouses is indicated, this population is of low risk for HIV positivity. Furthermore, continued screening of human sera used to make tissue culture media for IVF is mandatory.

Ovarian stimulation for in vitro fertilization in low-responder patients using pulsatile intravenous follicle stimulating hormone.

There is a subset of patients who fail to respond adequately to exogenous gonadotropin stimulation for in vitro fertilization (IVF). In this study, six such low-responder patients who had inadequate stimulations with high-dose intramuscular (im) follicle stimulating hormone (FSH) were treated in a subsequent cycle with pulsatile intravenous (iv) FSH. A paired analysis was performed to compare the cycles using high-dose im FSH with those using pulsatile iv FSH. Trough serum FSH levels were significantly higher with pulsatile iv FSH. No significant difference was noted in the stimulation characteristics or the number or quality of oocytes retrieved and embryos transferred. No pregnancies occurred in either group. While pulsatile iv administration of gonadotropin increases serum FSH levels, it does not appear to have a major impact on follicular stimulation or outcome in low-responder patients undergoing IVF.

Single dose long-term suppression of testosterone secretion by a gonadotropin-releasing hormone antagonist (Antide) in male monkeys.

This study was designed to find the minimal single dose of Antide (Nal-Lys GnRH antagonist) that would provide long-term inhibition of serum testosterone levels in adult male monkeys. At 3 mg/kg (sc), Antide blocked testosterone secretion for only a few days. However, when the dose of Antide was raised to 10 mg/kg, some of the males manifested testosterone inhibition lasting more than 60 days, while shorter durations of action were found in others. These preliminary findings increase our interest in studying Antide as a potential male contraceptive agent, when combined with androgen replacement therapy, as well as for therapeutic applications in men having prostatic carcinoma. Importantly, Antide lacks the sometimes deleterious "flare" effect known to occur when GnRH agonists are used to treat these patients.

Ovarian stimulation for in vitro fertilization using pure follicle-stimulating hormone with and without gonadotropin-releasing hormone agonist in high-responder patients.

There is a distinct pattern of response to gonadotropin stimulation in some patients marked by high peak estradiol (E2) levels, multifollicular ovarian response, and elevated basal luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratios. We reviewed the stimulation profiles of five such high-responder patients who failed to conceive during in vitro fertilization with ovarian stimulation using pure FSH. All patients had baseline LH/FSH greater than 1.5 and peak E2 greater than 800 pg/ml. One cycle was canceled prior to hCG administration because of marked ovarian response (E2 greater than 2500 pg/ml, multiple small follicles). In a subsequent cycle, all patients were pretreated with the gonadotropin releasing-hormone agonist (GnRHa) leuprolide acetate for 10-14 days prior to initiation of FSH for ovarian stimulation. Leuprolide was continued until the day of hCG administration. During cycles using GnRHa, there was a statistically significant decrease (P less than 0.05) in serum FSH on day 3 (less than 5 vs 8.3 mIU/ml), serum E2 on day 3 (14.6 vs 34.6 pg/ml), and peak serum E2 (1197.6 vs 1923.0 pg/ml). Patients during cycles with GnRHa had a greater number of preovulatory (8.6 vs 3.0) and total (12.4 vs 6.0) oocytes retrieved (P less than 0.05). The fertilization rate of preovulatory oocytes was also higher during cycles using GnRHa (83 vs 64%). Two pregnancies occurred in the cycles pretreated with GnRHa. These preliminary data indicate that in high-responder patients, a combination of GnRHa and pure FSH results in lower E2 levels during the stimulation cycle and a greater number of total and mature oocytes retrieved and fertilized.

Equivalency of human menopausal gonadotropin and follicle-stimulating hormone stimulation after gonadotropin-releasing hormone agonist suppression.

This study compares the use of human menopausal gonadotropin (hMG) versus follicle-stimulating hormone (FSH), after gonadotropin-releasing hormone agonist (GnRH-a) suppression for in vitro fertilization. Thirty-seven patients were randomized to ovarian stimulation with either hMG or pure FSH. The GnRH-a leuprolide acetate was administered to all patients beginning in the midluteal phase of the prior cycle and continuing until the day of human chorionic gonadotropin (hCG) administration. There were no significant differences between hMG and FSH cycles with regard to the day of hCG administration, mean peak estradiol levels, number of ampules of medication used, and number of oocytes aspirated, embryos transferred, or pregnancies. We conclude that there is no significant difference between hMG and FSH stimulation when used in conjunction with GnRH-a.