Nutrient Sensing Receptors

A small family of GPCRs with low homologies to other receptors has recently been identified.167 GPRs 40, 41, and 43 share 30 to 40% sequence identities to one another. Ligands for these receptors have been identified as long-chain fatty acids

(GPR40) and short-chain carboxylic acids (GPR41 and GPR43).168-171 Long-chain fatty acids serve as energy sources and also have the potential to be converted to signaling molecules within cells. Excess long-chain fatty acids are known to induce insulin resistance and contribute to metabolic derangements in diabetes and obesity.172 The identification of fatty acid receptors presents the intriguing possibility that some of the recognized metabolic effects of circulating free fatty acids may occur via these GPCRs.

GPR40 is expressed most highly in brain and in pancreatic beta cells. It has been shown that long-chain free fatty acids enhance glucose-dependent insulin secretion from beta cells through activation of GPR40.173 Some selectivity for specific fatty acids was found, with saturated free fatty acids of chain length C12-16 and unsaturated free fatty acids of chain length C18-20 preferred. Some eicosanoids also showed receptor stimulatory activities comparable to those of the long-chain fatty acids. GPR41 is expressed in a number of tissues including white fat. Activation of this receptor in fat cells and in intact animals by short-chain fatty acids (C2-C6) led to stimulation of leptin production.171 Because circulating leptin levels are reflective of both adipose mass and nutritional status, an involvement of GPR41 in leptin secretion identifies a signaling role for short-chain fatty acids from the diet in this nutrient-sensing pathway. GPR43 has a limited distribution, and its selective expression in leukocytes suggests a role for this receptor in recruitment of these cells toward sites of infection rather than in energy homeostasis.169

Supplements For Diabetics

Supplements For Diabetics

All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.

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