Researchers Reveal Critical Processes During Insulin Secretion

Diabetes is a very serious disease that, if left untreated, can have life threatening consequences. And even when treated, on the long term its effects can still lead to severe complications on one or more systems or parts of the body. Many of the processes taking place during the release of the insulin hormone, which regulates the blood sugar concentrations, remained largely unknown until now when scientists revealed exactly what happens inside beta cells while releasing insulin in the blood stream.

One of the most important chemicals regulating the processes taking place inside cells is the so-called cyclic AMP universal messenger molecule. In beta cells, for example, it controls the release of insulin but also determines certain hormones to trigger the increase in insulin secretion. Yet, nobody was actually successful in establishing the role of the cAMP molecule during the release of high levels of insulin when the glucose concentrations inside the blood increase.

The new study conducted by Anders Tengholms of the Uppsala University shows that energy-rich molecules known as ATP produced during the metabolization of blood sugar can trigger a rise in the concentrations of cAMP molecules in the membrane of beta cells as insulin is released into the blood. At the same time the increase of concentration of the cAMP molecules is followed by the increase of calcium ion, which is a stimulant messenger varying its concentration accordingly to that of the cAMP molecules, thus triggering a pulsatile secretion of insulin.

This basically means that in order for the body to accurately regulate the release of insulin in concordance with the levels of glucose in the blood, the cAMP and calcium concentrations must be synchronized, to give rise to a pulsatile release of insulin characteristic to healthy persons.

The results of the study clearly show that beta cells stimulate the secretion of cAMP messenger molecules and how the cell regulates the cAMP concentrations. Additionally, the discovery that cAMPs play a key role in the metabolism of the cell and in the secretion of the insulin hormone suggests that the same molecule may also be responsible for gene regulation, cell growth and survival.