Lesions of the lateral hypothalamus (LH) cause hypophagia. However, activation of glutamatergic neurons in LH inhibits feeding. These results suggest a potential importance for other LH neurons in stimulating feeding. Our current study in mice showed that disruption of GABA release from adult LH GABAergic neurons reduced feeding. LH GABAergic neurons project extensively to the paraventricular h...

with open hepatectomy. The indications for LH have gradually expanded, from local resection of benign neoplasms at the liver edge to hemihepatectomy and more extensive anatomical resections, segmentectomy for malignant neoplasms, and donor hepatectomy for liver transplantations. The numbers of LH procedures performed are increasing exponentially in surgical centers worldwide [1,2]. In some high...

To investigate endocrine mechanisms associated with the occasional occurrence of fertile oestrus during lactation in the high prolific Chinese Meishan (MS) breed, the incidence of oestrus and changes in plasma luteinizing hormone (LH) levels before and after oestradiol benzoate (OB, 15 micrograms/kg body weight) administration on day 22 was compared in 4 MS and 6 Large White (LW) sows. All sows...

The physiological role of luteinizing hormone-releasing hormone (LH-RH) in mediating the secretion of gonadotrophins is well established. However, administration of large doses of LH-RH produces a paradoxical anti-fertility effect. Thus, in women, agonists of LH-RH have been shown to inhibit ovulation (Nillius, Bergquist & Wide, 1978) and interfere with corpus luteum function (Casper & Yen, 197...

The incremental nature of neuroendocrine aging suggests that subtle system dysregulation may precede overt axis failure. The present analyses unmask threefold disruption of pulsatile gonadotropin-releasing hormone (GnRH)-luteinizing hormone (LH) secretion in the aging male. First, by way of random effects-based deconvolution analysis, we document an elevated daily GnRH-LH pulse frequency in hea...

Neuropeptide Y (NPY) is a putative mediator of many physiological processes in the central nervous system including reproductive functions. In this study we examined the effect of NPY on the GnRH/LH secretory activity in early anoestrous ewes. Crossbreed ewes one week (group 1w, n=7) and six weeks (group 6w, n=7) after the last oestrous cycle were infused with Ringer solution (control) or 50 mi...

Reproductive aging is characterized by delayed and attenuated luteinizing hormone (LH) surges apparent in middle-aged rats. The suprachiasmatic nucleus (SCN) contains the circadian clock that is responsible for the timing of diverse neuroendocrine rhythms. Electrophysiological studies suggest vasoactive intestinal peptide (VIP) originating from the SCN excites gonadotropin-releasing hormone (Gn...

During spring sheep do not normally ovulate but exposure to a ram can induce ovulation. In some ewes an LH surge is induced immediately after exposure to a ram thus raising questions about the control of this precocious LH surge. Our first aim was to determine the plasma concentrations of oestradiol (E2) E2 in anoestrous ewes before and after the "ram effect" in ewes that had a "precocious" LH ...

The impact of suppressed concentrations of circulating luteinizing hormone (LH) during ovarian stimulation on the outcome of in-vitro fertilization or intracytoplasmic sperm injection treatment in 200 consecutive, normogonadotrophic women (couples) was analysed retrospectively. A standard stimulation protocol with mid-luteal gonadotrophin-releasing hormone (GnRH) agonist down-regulation and ova...

It is well known that majority of patients with collagen diseases are women and that collagen diseases take turn for the worse or the better when the secretion of sex hormones changes greatly at menarche, pregnancy, delivery or menopause. These facts suggest that sex hormones are involved in the pathophysiology of collagen diseases. In the present study, the responses of plasma luteinizing horm...