Glucose inhibits insulin release induced by Na+ mobilization calcium

Received 8 September 1982 45Ca2+incorporated in response to glucose was selectively mobilized from the /?-cell-rich pancreatic islets of ob/ob-mice after raising the intracellular Na + by removal of K + or addition of ouabain or veratridine. Also studies of insulin release indicated opposite effects of glucose and Na + on the intracellular sequestra- tion of calcium. The fact that glucose inhibits insulin release induced by raised intracellular Na+ indicates that this sugar can lower the cytoplasmic [Ca 2+] . The concept of a dual action of glucose on the cyto- plasmic [Ca2+]. The concept of a dual action of glucose on the cytoplasmic [Ca2+ d might well explain previous observations of an inhibitory component in the glucose action on the 5Ca +efflux.