Gonadal function is critically dependant on regulated secretion of the gonadotropin hormones from anterior pituitary gonadotroph cells. Gonadotropin biosynthesis and release is triggered by the binding of hypothalamic GnRH to GnRH receptor expressed on the gonadotroph cell surface. The repertoire of regulatory molecules involved in this process are still being defined. We used the mouse L beta ...

In mammals, gonadal function is controlled by the activity of hypothalamic gonadotropin-releasing hormone neurons, which control the secretion of adenohypophyseal and gonadal hormones. However, there are a number of unanswered questions in relation to gonadal function. It is currently unknown how erotogenic stimulation of the genitals influences the subpopulation of hypothalamic medial preoptic...

The amyloid-beta precursor protein (AbetaPP) is a ubiquitously expressed adhesion and neuritogenic protein whose processing has previously been shown to be regulated by reproductive hormones including the gonadotropin luteinizing hormone (LH) in human neuroblastoma cells. We report for the first time the expression of AbetaPP in human embryonic stem (hES) cells at the mRNA and protein levels. U...

The normal physiology of the female reproductive system involves a hypothalamus that secretes gonadotropin-releasing hormone (GnRH)in a pulsatile manner, a pituitary gland that can be stimulated by the hypothalamus to regularly secrete both luteinizing hormone (LH) and follicle-stimulating hormone (FSH), an ovary that has both methodical enzymatic system and steroidogenesis for producing the se...

The direct regulation of testis androgen and progestin biosynthesis by neurohypophysial hormones was investigated in a primary culture of rat testis cells. Treatment with arginine vasotocin (AVT; 10(-6) M) over a 10-day period inhibited the human chorionic gonadotropin (hCG)-stimulated testosterone accumulation while enhancing hCG-stimulated progesterone accumulation. Furthermore, treatment wit...

Acute and chronic exposure to high altitude induces various physiological changes, including activation or inhibition of various hormonal systems. In response to activation processes, a desensitization of several pathways has been described, especially in the adrenergic system. In the present study, we aimed to assess whether the hypophyseal hormones are also subjected to a hypoxia-induced decr...

Lutropin (LH) bears asparagine-linked oligosaccharides terminating with the unique sequence SO4-4GalNAc beta 1-4GlcNAc beta 1-2Man alpha, whereas follitropin (FSH) bears oligosaccharides terminating predominantly with the sequence Sia alpha-Gal beta 1-4GlcNAc beta 1-2Man alpha, where Sia is sialic acid. We previously identified a glycoprotein-hormone-specific N-acetylgalactosamine-transferase (...

The Goodwin oscillator is a simple yet instructive mathematical model, describing a wide range of self-controlled biological and biochemical processes, among which are selfinhibitory metabolic pathways and genetic circadian clocks that lead to important applications, such as the hormonal cycles modeling. Indeed, one of the first models of hormonal rhythm, squarely based on the conventional Good...

Although epidemiologic evidence for the ability of combined oral contraception (OC) to reduce the risk of ovarian cancer (OvCa) is convincing, the biological mechanisms underlying this effect are largely unknown. We conducted the present study to determine if OC also influences ovarian carcinogenesis in a genetic mouse model and, if so, to investigate the mechanism underlying the protective eff...