Intercellular Ca2+ waves sustain coordinate insulin secretion in pig islets of Langerhans

Abstract

Insulin release was investigated in parallel with changes in cytosolic calcium concentration, [Ca²⁺]_i, in pig islets stimulated by glucose. After two days in culture, glucose stimulation failed to induce insulin release, and caused limited [Ca²⁺]_i changes in few cells. After ten days, insulin response was partially restored and [Ca²⁺]_i recordings revealed a slow oscillatory activity of the whole islet. Slow oscillations appeared to be due to the average [Ca²⁺]_i variations resulting from the spreading of waves throughout the islet. These waves demonstrate the reestablishment of functional cell coupling, which appears to play a critical role in insulin release.