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...

Basal and LH-RH induced plasma FSH and LH levels were determined longitudinally in 41 patients aged 4 to 22 years with Turner's syndrome and in 4 male patients with prepubertal castration. In 12 patients with Turner's syndrome over 18 yrs of age without pubertal change, basal and LH-RH induced FSH levels studied at age 11--22 yrs were all significantly increased over normal levels. However, som...

BACKGROUND Theca cells play an important role in controlling ovarian steroidogenesis by providing aromatizable androgens for granulosa cell estrogen biosynthesis. Although it is well established that the steroidogenic activity of theca cells is mainly regulated by LH, the intracellular signal transduction mechanisms that regulate thecal proliferation and/or steroidogenesis remain obscure. In th...

Three species of luteinizing hormone (LH) designated as LH-A, -B, and -C, and containing 9, 8, and 4 NIH-LH-Sl units per mg were isolated from human pituitary glands by isoelectric focusing. The LH-A, -B, and -C each sedimented as a single boundary in the ultracentrifuge with ~20,~ of 2.34, 2.24, and 2.70 S, respectively. Amino acid analyses of LH-A, -B, and -C were very similar, although minor...

We compared five two-site immunometric assays (including three commercially available kits) for measuring lutropin (LH) in serum. Four of the assays involved monoclonal antibodies directed against the alpha-beta dimer, intact LH; these assays measured significantly lower concentrations of LH in 19 (out of 83) samples than did a commercial method not involving such antibodies. In five serum samp...

We assessed the time-dependent impact of estradiol on properties of the luteinizing hormone (LH) pulse signal in 12 hypoestrogenemic postmenopausal volunteers studied basally and after 1, 5, 10, and 30 d of estradiol delivery via an intravaginal Silastic ring. Computerized analysis of the plasma LH time series revealed a significant decrease in LH pulse frequency within 24 h of estrogen treatme...

Luteinizing hormone (LH) secretory profiles have been determined for the male bovine following castration and steroid replacement therapy. Serum LH concentrations increased approximately threefold during the first week following castration and thereafter remained elevated (6.6 +/- .7 ng/ml). Castrates not receiving steroid replacement showed a rhythmic pattern of LH release that was of high fre...