Biological activities of human growth hormone and its derivatives estimated by measuring DNA synthesis in Nb2 node rat lymphoma cells
| Autor: | Yoshito Ohba, Kae Wakai, Motoyasu Saji, Naoya Emoto, Mariko Arai, Kazuo Shizume, Toshio Tsushima, Toshiaki Tanaka, Eiji Ohmura |
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| Rok vydání: | 1987 |
| Předmět: |
endocrine system
medicine.medical_specialty Lymphoma Endocrinology Diabetes and Metabolism Biology Cell Line chemistry.chemical_compound Endocrinology Internal medicine Protein biosynthesis medicine Animals RNA Neoplasm Receptor chemistry.chemical_classification Dose-Response Relationship Drug DNA synthesis Cell growth Biological activity DNA Neoplasm Receptors Somatotropin General Medicine Neoplasm Proteins Rats Amino acid Cell Transformation Neoplastic chemistry Cell culture Growth Hormone embryonic structures hormones hormone substitutes and hormone antagonists DNA |
| Zdroj: | Acta Endocrinologica. 114:283-291 |
| ISSN: | 1479-683X 0804-4643 |
| DOI: | 10.1530/acta.0.1140283 |
| Popis: | Nb2 cell is a rat lymphoma cell line that responds to lactogens such as prolactin and human growth hormone (hGH) with an increased rate of proliferation. We explored the relationship between the biochemical events induced by hGH and its derivatives and their receptor binding activities. hGH stimulated RNA, DNA and protein synthesis of Nb2 cells as a function of time. Stimulation of RNA and protein was maximal at 2–3 h and 12 h, respectively, after the addition of hGH. DNA synthesis, measured by the rate of [3H]thymidine incorporation, reached a maximum after 18-h incubation with hGH. Stimulation of DNA synthesis was elicited by hGH in a dose-dependent manner between 0.45 and 45 pmol/l. The activity of the 20 K hGH variant in stimulating DNA synthesis was approx 30% of that of hGH. In contrast, S1-hGH, which lacks a sequence of ten amino acids (140–149) of hGH, showed a 3.2-fold greater activity than hGH. F1 (aminoterminal sequence 1–134 of hGH) was only 0.06% as active as hGH, and the activity of F2 (C-terminal 42 amino acid residue of hGH) was less than 0.01%. Both fragment 1–15 and 32–46 were without effect. The relative potencies of these hGH derivatives in stimulating DNA synthesis were similar to their relative abilities to inhibit [125I]hGH binding to lactogenic receptors on Nb2 cell. Nb2 cells provide a suitable model to study the relationship between receptor binding and the biochemical events induced by lactogens. |
| Databáze: | OpenAIRE |
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