INCRETINS which were discovered in the saliva of a Gila Monster in 1965 have been on the market for the last two years in the synthetic form, mainly pramlitide with the brand name of SYMALIN . The incretins are at least two hormones that work naturally to balance insulin secretion and sugar (glucose) regulation from other endocrine target organs. There are two main incretin hormones in humans. They are GIP (glucose-independent insulinotropic peptide) and GLP-1 (glucagon-like peptide -1). Both hormones are secreted by the endocrine cells, L and T respectively in the intestinal lining in response to glucose in the gut. The glucose is from the break down of sugars and starches that we eat. The hormone, which is then absorbed, goes into our circulation and travels to the various target organ receptors. Therefore in addition to the food we consume this is yet another mechanism that controls our metabolic state and fat production. The excess calories that we absorbed if not going to manufacture protein produces fat! In yesteryear we needed this extra fat for times of famine. But now in times of plenty it is harmful and in those who are so genetically disposed, which is 25% of our population, leads to excess blood sugar (Diabetes).
The PANCREAS has both Alpha and Beta cells. The Beta secretes INSULIN and AMYALIN, while the Alpha, produces GLUCAGON. Glucagon stimulates the liver to release glucose from its store of glycogen and to manufacture glucose from fat and protein. This raises the blood sugar and is normally secreted in time of need and in adrenal response to stress. Hence glucagon is elevated in physical trauma and mental pressure which raises blood sugar. AMYLIN or artificially SYMALIN, suppresses Glucagon release thus lowering the blood sugar by slowing its production from the liver.
Symalin also binds to the receptors in the area postrema in the BRAIN. This causes satiety and suppresses the appetite. Moreover this substance again mimicking Amylin slows STOMACH emptying into the intestine causing less food (glucose) into the digestive tract for absorption. These mechanisms together lower the blood sugar in diabetics and decrease fat production in the normal person. Another form of Amylin is BYETTA also used to treat diabetes. Both of these are by subcutaneous injections. The Symylin is given before meals with insulin and the Byetta with or without insulin. It is more than coincidence both are manufactured by the same company, Amylin Pharmaceuticals, Inc. Both are overridden by a sudden decrease of blood sugar, but because of the extreme effect of taking insulin, the usual dose can be reduced by as much as 50%.
Since both Byetta and Symalin decrease appetite by controlling both the brain and stomach they do help to weight loss. I have given both in patients on off- label use for weight (fat) control usually in pre-diabetics to prevent weight gain and in real diabetes. In the future there will be a long acting Byetta given weekly and a Symalin combination. The later will be with two natural hormone look a-likes. LEPTIN and NEUROPEPTIDE –Y. All three of these will work in concert for weight reduction, which is so needed in the 21st century.