A new progesterone antagonist, ulipristal has been made available as an emergency contraceptive. Ulipristal's major mechanism of action as an emergency contraceptive has been ascribed to its ability to delay ovulation beyond the life span of the sperm. This paper analyzes the potential action of ulipristal (1) when unprotected intercourse and administration of ulipristal occur outside the ferti...

Females of some bird species have a high degree of control over the sex ratio of their offspring at laying. Although several mechanisms have been put forward to explain how females might control the sex of their eggs, virtually nothing is known. As females are the heterogametic sex in birds, adjustment of the clutch sex ratio could arise either by pre- or post-ovulation control mechanisms. The ...

SUZUKI, M., OSAWA, S. and HIRANO, M. A Lyeium Chinense Miller Component Inducing Ovulation in Adult Female Rabbits. Tohoku J. exp. Med., 1972, 106 (3), 219-231Intravenous injection of the crude extract from Lycii folium among components of Lycium chinense Miller induced ovulation in the adult female rabbit. Chemical properties of the active component of this crude extract were investigated by d...

Brief exposure to some pesticides, applied during a sensitive window for the neural regulation of ovulation, will block the preovulatory surge of LH and, thus, delay ovulation. Previously, we have shown that a single i.p. injection of 50 mg/kg of thiram, a dithiocarbamate fungicide that decreases norepinephrine synthesis, on proestrus (1300 h) suppresses the LH surge and delays ovulation for 24...

Fifty-six squirrel monkeys were studied to develop means of accurate ovulation induction. Ovaries were exposed to determine ovulation time. Pre-treatment with progesterone to suppress spontaneous ovulation (5 mg daily for 5 days) was followed by : (a) no fsh, (b) 1 mg fsh, (c) human menopausal gonadotrophin (hmg), equivalent to 75 i.u. fsh, or (d) 200 i.u. pregnant mare's serum gonadotrophin (p...

Ovulation is essential for the propagation of the species and involves a proteolytic degradation of the follicle wall for the release of the fertilizable oocyte. However, the precise mechanisms for regulating these proteolytic events are largely unknown. Work from our lab and others have shown that there are several parallels between Drosophila and mammalian ovulation at both the cellular and m...

Patients suffering from normogonadotrophic anovulation and infertility are initially treated with clomiphene citrate. Those who do not respond to clomiphene citrate usually receive gonadotrophin treatment which is labour-intensive, expensive, and associated with an increased risk of multiple pregnancies and ovarian hyperstimulation syndrome. We treated 22 patients with clomiphene resistant norm...

Survival of embryos exposed to several concentrations of uterine proteins and changes in tubal morphology in rabbits given low preovulatory doses of progesterone (P4) that had previously not affected ovulation or fertilization, but caused severe embryo mortality, were studied. In experiment 1, 332 morulae were cultured for 24 h in a control medium containing < 0.5 to > 3.0 mg x mL(-1) of Day 3 ...

BACKGROUND Lymphocytic hypophysitis is an unusual autoimmune disease that causes partial or total hypopituitarism and often is associated with pregnancy. Only four spontaneous pregnancies have been reported after this disease. We report a case of ovulation induction in a woman with this antecedent as well as the course of the subsequent pregnancy. CASE Ovulation was induced with gonadotropins...