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.