Involvement of both calcium influx and calcium mobilization in growth hormone-induced [Ca2+]i increases in Chinese hamster ovary cells
| Autor: | L Barakat, Jean Djiane, G Boquet, Jacqueline Paly, Bernard Dufy |
|---|---|
| Přispěvatelé: | Unité de biologie cellulaire et moléculaire, Institut National de la Recherche Agronomique (INRA) |
| Rok vydání: | 1997 |
| Předmět: |
Intracellular Fluid
Dihydropyridines medicine.medical_specialty Patch-Clamp Techniques [SDV]Life Sciences [q-bio] chemistry.chemical_element CHO Cells Calcium Biology Biochemistry Calcium in biology Endocrinology Cricetinae Internal medicine medicine Extracellular Animals Patch clamp Molecular Biology ComputingMilieux_MISCELLANEOUS Calcium metabolism Voltage-dependent calcium channel Chinese hamster ovary cell SPECTROFLUORIMETRIE Electrophysiology Verapamil chemistry Growth Hormone Thapsigargin Calcium Channels Rabbits |
| Zdroj: | Molecular and Cellular Endocrinology Molecular and Cellular Endocrinology, Elsevier, 1997, 131, pp.109-120 |
| ISSN: | 0303-7207 |
| DOI: | 10.1016/s0303-7207(97)00105-6 |
| Popis: | This study reports rapid effects of growth hormone (GH) on the intracellular free calcium concentration ([Ca2+]i) in Chinese hamster ovary (CHO) cells stably expressing rabbit GH receptor. [Ca2+]i was measured by spectrofluorimetric methods in single cells and membrane Ca2+ currents by patch clamp techniques in the whole-cell configuration. In individual CHO cells, bathed in a standard saline solution containing 2 mM Ca2+, basal [Ca2+]i was 191 +/- 27 nM (mean +/- S.D.; n=83). Short term administration of GH (100 ng/ml, 30 s) induced a [Ca2+]i increase in 54% of cells tested (n = 398 of 743). Responses were clearly heterogeneous. Maximum calcium increase varied from 16 to 853 nM and time to peak varied from 4 to 320 s. On examination of the [Ca2+]i increases, it was possible to define two different types of calcium responses to GH. Experimental manipulations of extracellular and intracellular calcium concentrations demonstrated that GH-induced calcium increases involved both calcium influx and calcium mobilization. Calcium influx, a long lasting, small amplitude (63 +/- 34 nM) response, was observed in 121 out of 398 cells (30%) whereas calcium mobilization, a transient, large amplitude (263 +/- 175 nM) response, was observed in 277 out of 398 cells (70%). Moreover, patch clamp data show that influx did not involve the dihydropyridine-sensitive calcium channels. |
| Databáze: | OpenAIRE |
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