Synchronous glucose-dependent [Ca(2+)](i) oscillations in mouse pancreatic islets of Langerhans recorded in vivo.
Using microfluorescence in combination with image-analysis techniques we monitored intracellular calcium ([Ca(2+)](i)) dynamics in mouse islets of Langerhans loaded with fura-2 and recorded in vivo. [Ca(2+)](i) oscillates in the glycaemias range 5-10 mM, the duration of the oscillations being directly proportional to the blood glucose concentration. The analysis of different areas within the same islet shows that [Ca(2+)](i) oscillations are synchronous throughout the islet. These results show that in vivo, individual islets of Langerhans behave as a functional syncytium and suggest the existence of secretory pulses of insulin.
Fernandez
J
J
Instituto de Neurociencias-CSIC, Universidad Miguel Hernandez, 03550 San Juan, Alicante, Spain.
Valdeolmillos
M
M
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D005453:Fluorescence; D016257:Fura-2 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice
D001786:Blood Glucose; D005947:Glucose; D002118:Calcium; D016257:Fura-2