Pulsatile insulin release: role of cytoplasmic Ca2+ oscillations

Diabetes Metab. 1998 Feb;24(1):41-5.

Abstract

Oscillations of plasma insulin are essential for the hypoglycaemic effect of the hormone. Disturbance and partial loss of these oscillations occur during the development of Type 2 diabetes, in association with down-regulation of insulin receptors and insulin resistance. Oscillations with a frequency similar to that of plasma insulin have been observed in the cytoplasmic Ca2+ concentration ([Ca2+]i) of pancreatic beta cells, indicating that the ion plays a role in generating insulin pulses. Studies of individual islets have revealed that oscillations of [Ca2+]i and insulin release are synchronous. However, insulin release is also pulsatile under conditions in which [Ca2+]i is stable. These results support the notion that variations in the ATP/ADP ratio are sufficient to induce pulsatile insulin release. Under physiological conditions, this pulsatility may depend on the synergistic effects of ATP/ADP and [Ca2+]i oscillations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Cytoplasm / metabolism*
  • Humans
  • Insulin / metabolism*
  • Insulin Secretion
  • Oscillometry
  • Secretory Rate

Substances

  • Insulin
  • Calcium