Some Properties of the Plasma hGH Activity in Patients with Laron-Type Dwarfism Determined by a Radioreceptor Assay Using Human Liver Tissue

Eshet, R; Peleg, Sagit; Josefsberg, Z; Fuchs, Camil; Arnon, Ruth; Laron, Zvi

doi:10.1159/000180106

Cited by 13 publications

(4 citation statements)

References 16 publications

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“…The quantity of microsomal proteins was measured by the method of Lowry et al (1951), using human serum albumin as a standard. The microsomal fraction was frozen and thawed 3 times and then kept frozen until used for the binding studies (Bergeron et al, 1978 (Eshet et al, 1985 was also lower than controls (85.6 4-2% of control, P < 0.01) but higher than the 30d DM animals (21.7 4-0.61 vs. 18.3 4-0.82 grams; P < 0.01) (Fig. la) (Fig.…”

Section: Receptor Preparationmentioning

confidence: 93%

Changes in the Growth Hormone‐IGF‐I Axis in Non‐obese Diabetic Mice

Landau

Segev

Eshet

et al. 1999

Journal of Diabetes Research

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Section: Receptor Preparationmentioning

confidence: 93%

Changes in the Growth Hormone‐IGF‐I Axis in Non‐obese Diabetic Mice

Landau

Segev

Eshet

et al. 1999

Journal of Diabetes Research

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“…When aliquots of fractions of serum, obtained after gel filtration or isoelectric focusing are assayed by RIA, RRA and NB2 cells, a close correlation between estimates of GH content by all three assays is found in each of the fractions collected. In particular, with Laron dwarfism the high serum concentrations of GH measured by RIA are also elevated when an RRA is used (14). These results indicate that the predominant circulating forms of 0.84 f 0.4 (7) 0.73 f 0.2 (6) 0 hGH react to an equivalent degree in each of the assays, suggesting that the assays can, for the most part, be used interchangeably.…”

Section: Acta Paediatr Scand [Suppl] 370mentioning

confidence: 87%

Receptor Assays For Growth Hormone

Friesen

1990

Acta Paediatrica

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Growth hormone (GH) assays are designed to determine the biological effectiveness of GH in a variety of preparations or in biological fluids (e.g. blood samples). Assays are important for the standardization of different GH preparations as well as for the evaluation and diagnosis of clinical disorders of growth. As shown in Table I , GH assays can be divided into four types.Two classical bioassays for GH were established over 40 years ago. The first depends on the body weight gain seen in hypophysectomized rats following a 10-day period of daily injections of GH. In the second, the 'tibia assay', the widening of the cartilage growth plate of the tibia of hypophysectomized rats is determined following four daily injections of GH. Purified or recombinant GH preparations are standardized on the basis of these two assays (1). Unfortunately, both assays have low sensitivity. Therefore, these assays are not suitable for the routine measurement of GH in serum samples.The development and application of radiommunoassays (RIAs) for GH dramatically changed our understanding of the secretion of GH in health and disease because, for the first time, circulating levels of GH could be measured relatively easily in a large number of samples. Using RIAs, basal levels of GH in the circulation were established, a sleep-related peak of GH was found, and hypoglycaemia and arginine infusion were found to be potent stimuli of GH secretion. Pharmacological agents, such as L-dopa-propranolol, were also shown to be potent stimuli for GH secretion. The RIA measurement of serum GH levels following provocative stimuli was widely used as a diagnostic test for GH deficiency (2). Whilst GH immunoassays were convenient and appeared satisfactory in identifying GHdeficient patients, a lingering concern persisted that, at least in some patients, there were discrepancies between the levels of the biologically active form of GH in the circulation and the immunoassay estimates. The most dramatic example of this was found by Ellis et al.. who reported much higher values of GH by the tibia assay than by RIA of plasma samples (3).In the absence of a specific and sensitive bioassay that matched the sensitivity of RIAs, the Table 1. Type of GH assay. Description Sensitivity (ng) Bioassays ( i l l virro) Hypophysectoniized rats Body weight gain Tibia width Radioimniunoassay Radioreceptor assay (liver) IM9 lymphocytes Receptor modulation assay NB2 node lymphoma cells (lactogenic)5000 ( X 10)' 2000 ( X 4)' 0.5 20.0 10.0 2.0 0.5 'Numhers in parentheses indicate that GH must be injected in the amounts shown for 10 or 4 days. respectively.

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“…The bold diagonal line in the graph represents points where the ratio of the bioassay value to the IRMA value equaled to 1. sample, but rather reflect the combined immunoreactivity of the compounds structurally related to the immunogen (12). To overcome the shortcomings of immunoassays, bioassays have been developed, based on the binding of GH to GHRs, with GHR preparations being in the form of plasma membrane preparations (13)(14)(15)(16)(17) or as cell lines expressing GHR, such as the human lymphoblastoid line IM-9 (18). However, these methods require tissue culture facilities or preparation of plasma membrane fractions; moreover, they were relatively not sensitive.…”

Section: Discussionmentioning

confidence: 99%

Development of a Bioassay System for Human Growth Hormone Determination with Close Correlation to Immunoassay

Maimaiti¹,

Tanahashi

Mohri

et al. 2012

Clinical Laboratory Analysis

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Serum growth hormone (GH) level is measured largely through immunoassays in clinical practice. However, a few cases with bioinactive and immunoreactive GH have also been reported. We describe here a new bioassay system for GH determination using the BaF/GM cell line, which proliferates in a dose-dependent manner on hGH addition; cell proliferation was blocked by anti-hGH antibody. This bioassay had the lowest detection limit (∼0.02 ng/ml) reported thus far and the highest specificity for GH. The bioassay results were compared with those of an immunoradiometric assay across 163 patient samples in various endocrine states. A close correlation (the ratio of bioactivity/immunoreactivity was 1.04 ± 0.33, mean ± SD) was observed between bioactivity and immunoreactivity in these samples. The newly developed system is a specific, sensitive, easy, and fast bioassay system for GH determination; we consider it useful for evaluating GH bioactivity in various endocrine states.

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Some Properties of the Plasma hGH Activity in Patients with Laron-Type Dwarfism Determined by a Radioreceptor Assay Using Human Liver Tissue

Cited by 13 publications

References 16 publications

Changes in the Growth Hormone‐IGF‐I Axis in Non‐obese Diabetic Mice

Changes in the Growth Hormone‐IGF‐I Axis in Non‐obese Diabetic Mice

Receptor Assays For Growth Hormone

Development of a Bioassay System for Human Growth Hormone Determination with Close Correlation to Immunoassay

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