Time and amplitude regulation of pulsatile insulin secretion by triggering and amplifying pathways in mouse islets

FEBS Letters

Henquin, Jean-Claude¹  Ravier, Magalie A¹ 

[1] Unité d'Endocrinologie et Métabolisme, University of Louvain Faculty of Medicine, UCL 55.30, Avenue Hippocrate 55, B-1200 Brussels, Belgium

关键词: Insulin secretion;    Oscillation;    Glucose;    Calcium;    Pancreatic islet;    Diabetes;   

DOI  :  10.1016/S0014-5793(02)03491-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Glucose-induced insulin secretion is pulsatile. We investigated how the triggering pathway (rise in β-cell [Ca²⁺]_i) and amplifying pathway (greater Ca²⁺ efficacy on exocytosis) influence this pulsatility. Repetitive [Ca²⁺]_i pulses were imposed by high K⁺+ diazoxide in single mouse islets. Insulin secretion (measured simultaneously) tightly followed [Ca²⁺]_i changes. Lengthening [Ca²⁺]_i pulses increased the duration but not the amplitude of insulin pulses. Increasing glucose (5–20 mmol/l) augmented the amplitude of insulin pulses without changing that of [Ca²⁺]_i pulses. Larger [Ca²⁺]_i pulses augmented the amplitude of insulin pulses at high, but not low glucose. In conclusion, the amplification pathway ensures amplitude modulation of insulin pulses whose time modulation is achieved by the triggering pathway.

【 授权许可】

Unknown