foto 1: Nature Biotechnology 23, 857 – 861 (2005) Published online: 7 July 2005
foto 2: source
Beta-cell mass regulation represents a critical issue for understanding diabetes, a disease characterized by a near-absolute (type 1) or relative (type 2) deficiency in the number of pancreatic beta cells. The number of islet beta cells present at birth is mainly generated by the proliferation and differentiation of pancreatic progenitor cells, a process called neogenesis. Shortly after birth, beta-cell neogenesis stops and a small proportion of cycling beta cells can still expand the cell number to compensate for increased insulin demands, albeit at a slow rate. The low capacity for self-replication in the adult is too limited to result in a significant regeneration following extensive tissue injury. Likewise, chronically increased metabolic demands can lead to beta-cell failure to compensate. Neogenesis from progenitor cells inside or outside islets represents a more potent mechanism leading to robust expansion of the beta-cell mass, but it may require external stimuli. For therapeutic purposes, advantage could be taken from the surprising differentiation plasticity of adult pancreatic cells and possibly also from stem cells. Recent studies have demonstrated that it is feasible to regenerate and expand the beta-cell mass by the application of hormones and growth factors like glucagon-like peptide-1, gastrin, epidermal growth factor, and others. Treatment with these external stimuli can restore a functional beta-cell mass in diabetic animals, but further studies are required before it can be applied to humans.
GLP-1 is an antidiabetic hormone, glucagon-like peptide-I, secreted by the ileum, which is the second part of the small intestine. This hormone is secreted promptly after ingestion of carbohydrates and fat, leading to increased release of insulin and inhibiting glucagon secretion by the pancreas. Antidiabetic hormone acts upon the stomach, decreasing acid secretion and gastric motility.
Monounsaturated fatty acids, Omega 3 and Omega 6, which predominates in olive and avocado, ileum, stimulating hormone secreting cells of diabetes, while saturated fatty acids found in dairy products and meat, have not this effect. Replacement of animal fats and polyunsaturated fatty acids, monounsaturated fatty acids in the diet can be a useful intervention to increase secretion of antidiabetic hormone, GLP-1.L