We have investigated the effects of ovariectomy (OVX) and photostimulation (PS) on anterior pituitary LH beta mRNA abundance and circulating levels of LH in the domestic turkey. The birds were divided into the following four treatment groups: non-PS SHAM, PS SHAM, non-PS OVX, and PS OVX. Photostimulation was initiated 7 days after OVX. Anterior pituitaries and blood samples were collected on Da...

Endometrial cancer (EC) is a hormone-dependent cancer that currently represents the most frequent malignancy of the female reproductive tract. The involvement of steroid hormones in EC etiology and progression has been reported. More recently, gonadotropins, and, in particular LH/hCG, are emerging as novel regulators of tumor progression. In the present review, we discuss the role of the LH/hCG...

Adult female rats were rendered anovulatory by continuous illumination. Pituitary LH of these constant estrous rats decreased with the time length of illumination. Acidic extract from the rat hypothalamus was injected into these rats through the carotid artery for testing LH-RF activity. The extract, if a dose more than 2 hypothalamic fragments per rat was given, induced ovulation. Ovulatory re...

Spontaneous physical activity (SPA) describes activity outside of formal exercise and shows large interindividual variability. The hypothalamic orexin/hypocretin peptides are key regulators of SPA. Orexins drive SPA within multiple brain sites, including rostral lateral hypothalamus (LH) and nucleus accumbens shell (NAcSh). Rats with high basal SPA (high activity, HA) show higher orexin mRNA ex...

A variety of studies in man and animals demonstrate that testosterone (T) is aromatized to estradiol (E) in the hypothalamus and limbic system. These observations suggested the possibility that conversion to E is an absolute requirement for the biologic activity of T on the hypothalamic-pituitary axis. Since this hypothesis implies a common mechanism of action of these two steroids, the demonst...

Luteinizing hormone (LH) has been shown to be the only hormone essential for maintenance of testicular testosterone pr0duction.l LH mediates its effect on testicular steroidogenesis by binding to high affinity receptors in the plasma membrane of Leydig cells. In recent years, numerous investigators have reported that in vivo administration of LH or human chorionic gonadotropin (hCG) results in ...

We investigated the possible clinical correlates between the serum LH concentration and characteristics of frailty and determined the presence and concentration of a genetic LH variant in an independently living population of elderly men. After exclusion of subjects with severe mobility problems and signs of dementia, 403 healthy men (aged 73-94 yr) were randomly selected from a population-base...

A sensitive and specific double antibody radioimmunoassay has been developed capable of measuring LH-RH in extracted human plasma. Thyrotropin releasing hormone, lysine vasopressin and most of LH-RH analogues did not appear to affect the assay. Hypothalamic extract and some of the LH-RH analogues produced displacement curves which were parallel to that obtained with the synthetic LH-RH. Sensiti...

The present study was designed to achieve the production and characterization of polyclonal antibody of luteinizing hormone (AntiLH) as a basic component of LH radioimmunoassay (RIA). The main objective was to improve the immunogenicity of LH by conjugation of LH with bovine serum albumin (LH: BSA) as a protein carrier using Ethyl dimethylaminopropyl Carbodiimide (ECDI). Production of Anti-LH w...

The “learned helplessness” (LH) model in rats is widely used a battery of tests to assess depression-like behaviour and the effects antidepressants. considered be suffi ciently valid, though having some limitations with reproducibility. This review discusses possibilities using for assessing symptoms depressive-like state pathogenesis depression, as well factors affecting reproducibility LH are...