Nonsuppressible insulin-like activity (NSILA). I. Development of a new sensitive competitive protein-binding assay for determination of serum levels
| Autor: | Carolyn J. Johnson, Don S. Schalch, Udo E. Heinrich, Janet G. Koch, Robert J. Schlueter |
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| Rok vydání: | 1978 |
| Předmět: |
medicine.medical_specialty
Hydrocortisone Endocrinology Diabetes and Metabolism medicine.medical_treatment Clinical Biochemistry Biology Nonsuppressible Insulin-Like Activity Biochemistry Glucagon Binding Competitive Iodine Radioisotopes Radioligand Assay Endocrinology Internal medicine medicine Animals Humans Proinsulin Hypophysectomy Triiodothyronine Insulin Ligand binding assay Biochemistry (medical) Somatomedin Rats Kinetics Sephadex Growth Hormone Carrier Proteins hormones hormone substitutes and hormone antagonists |
| Zdroj: | The Journal of clinical endocrinology and metabolism. 46(4) |
| ISSN: | 0021-972X |
| Popis: | Nonsuppressible insulin-like activity (NSILA), one of the GH-dependent somatomedins, is a polypeptide (∼5800 mol wt) which is largely bound to a carrier protein of approximately 70,000 Daltons. By employing 125I-labeled highly purified NSILA (∼200 mU/mg) and partially purified NSILA carrier protein derived from pooled human plasma, a competitive protein- binding assay for NSILA has been developed. By utilizing purified NSILA (3.8 μU/mg) as standard, this assay procedure is capable of measuring NSILA levels in extracts of human and rat sera under conditions of both normal and diminished GH concentrations. In this assay procedure, the endogenous NSILA carrier protein complex is first dissociated by Sephadex G-50 chromatography in 1 N HOAc (pH 2.3). This assay is quite specific relative to a number of hormones (insulin, proinsulin, human GH, ACTH, glucagon, thyroxine, and PRL) but may detect other somatomedins (A, C, and multiplication-stimulating activity) which, like NSILA, probably crossreact with NSILA c... |
| Databáze: | OpenAIRE |
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