Insulin secretion and intracellular Ca2+ rises in monolayer cultures of neonatal rat beta-cells
| Autor: | Jean-Louis Schwartz, Marsha A. Black, James F. Whitfield, Nicole Bégin-Heick, Geoffrey A.R. Mealing |
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| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Patch-Clamp Techniques Nifedipine medicine.medical_treatment Tolbutamide Biology Rats Sprague-Dawley Islets of Langerhans Internal medicine Insulin Secretion Extracellular medicine Animals Insulin Beta (finance) Cells Cultured Fetus Age Factors Depolarization Cell Biology Rats Membrane Endocrinology Glucose Potassium Calcium Female Calcium Channels Intracellular medicine.drug |
| Zdroj: | Cellular signalling. 6(8) |
| ISSN: | 0898-6568 |
| Popis: | Glucose-induced insuline release, glucose-induced rises in intracellular free Ca 2+ concentration ([Ca 2+ ] i ), and voltage-dependent Ca 2+ channel activity were assessed in monolayer cultures of β-vells 3–5 day-old rats. The glucose-stimulated insulin secretory responses and [Ca 2+ ] i rises were like those in adult rat β-cells rather than fetal rat β-cells. Voltage-dependent Ca 2+ channel antagonists decreased glucose-induced insulin secretion, aborted the [Ca 2+ ] 2 rise and, like deprivation of extracellular Ca 2+ , prevented the glucose-induced rise in [Ca 2+ ] i when added before the glucose challenge. The presence of nifedipine-sensitive, voltage-dependent Ca 2+ channels was demonstrated directly by measuring Ca 2+ currents using the whole-cell configuration of the patch-clamp technique and indirectly by measuring [Ca 2+ ] 1 after membrane depolarization by 45 mMm K + or 200 μM tolbutamide. Thus, in cultured β-cells of 3–5 day-old rats the coupling of glucose stimulation to Ca 2+ influx is essentially mature, in contrast to what has been reported for fetal or very early neonatal cells. |
| Databáze: | OpenAIRE |
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