Insulin has long been acknowledged as the main natural regulator of blood-sugar levels, and when it is not able to function properly within one’s body (due to type 1 or type 2 diabetes), dangerous consequences can result. Researchers have recently found that the protein apelin might be the key to an alternative mechanism to insulin in regulating blood-sugar levels, a finding that could be very significant for diabetics.
Type 1 diabetes, also known as juvenile diabetes, is characterized by the destruction of insulin producing beta-cells in the pancreas, diminishing the ability to control blood-sugar. Type 2 diabetes on the other hand most generally occurs through decreased insulin sensitivity, or insulin resistance, which also limits the ability to control blood-sugar levels. In order to compensate for the diminished insulin, or limited sensitivity, insulin injections are often required. Both forms of the disease are believed to be largely genetic, but type 2 diabetes especially is considered manageable and often preventable, through proper nutritional and exercise managements. Few alternatives to insulin have been found as a treatment for severe cases of diabetes.
The protein apelin is synthesized in various parts of the body, including the heart and kidneys, but is secreted in the highest abundance from adipose tissue (fat). Sugar, when regulated by healthy insulin levels, is also stored in adipose tissue. In obese individuals, and those with type 2 diabetes, adipose levels have been observed to be significantly higher, forming the basis for the current research. Past research has also suggested that apelin plays a significant role in controlling blood pressure.
The current research has discovered that because of apelin, cells, even those with diminished insulin function, “are equipped with a second pathway for the assimilation of glucose.” The entire mechanism in which apelin acts to regulate blood-sugar is in fact different to insulin, most notably that each has distinctive “receptors” that captures the compounds. This fact could enable the development of effective treatments based on apelin, according to the researchers.
This proposed alternative treatment could have the most profound impact of type 2 diabetics. Researchers observed in mice that in healthy mice, apelin has a minimal role in regulating blood-sugar. But in mice with type 2 diabetes, it was possible to trigger the apelin derived blood-sugar mechanism, which greatly improved the ability of these mice to regulate their blood-sugar levels.
The next step is confirming apelin’s role in human beings, which if successful, could lead to novel treatments for diabetics. The current are right on top of these goals as well: “We now have to check the action of this protein in man. In parallel, we are developing a synthetic molecule that may be used if the tests in man are positive,” states lead researcher Dr. Philippe Valet.
Source: Defeat Diabetes Foundation: Valet, Phillipe. Ciancia, Severine. Cell Metabolism press release. November 2008.