Abstract: ObjectiveTo identify the differences between acetylcholine(Ach)-induced increase and adenosine triphosphate(ATP)-induced increase in cytosolic free Ca²⁺ concentration ([Ca²⁺]c) in mouse pancreatic β-cells. MethodsMouse pancreatic β-cells were primarily cultured and divided into two groups,one group was stimulated by Ach and another by ATP.[Ca²⁺]c was recorded with Fura-2 in normal condition, chelation of extracellular Ca²⁺ by EGTA and depletion of intracellular Ca²⁺ stores by Thapsigargin.ResultsAch induced a transient peak increase and sustained increase in [Ca²⁺]c. ATP induced a transient peak increase and no sustained increase. Chelation of extracellular Ca²⁺ by EGTA eliminated the sustained increase induced by Ach, and did not eliminate the transient peak increase induced by Ach and ATP. Depletion of intracellular Ca²⁺ stores by Thapsigargin eliminated the transient peak increase induced by Ach and ATP and the sustained increase induced by Ach. ConclusionsAch induces intracellular Ca²⁺ release and the following Ca²⁺ release-activated Ca²⁺ influx, and ATP induces intracellular Ca²⁺ release, but blocks the following Ca²⁺ release-activated Ca²⁺ influx.

Key words: mouse, acetylcholine, adenosine triphosphate, pancreatic β-cells, intracellular Ca²⁺