Glucose-insulin system diabetes, types

Amin R, Ross K, Acerini CL, Edge JA, Warner J, Dunger DB. Hypoglycemia prevalence in prepubertal children with type 1 diabetes on standard insulin regimen use of continuous glucose monitoring system. Diabetes Care 2003 26(3) 662-7. 

Vanadium compounds have also been shown to be effective in animal models of insulin resistance and type 2 diabetes. Oral administration of vanadium compounds lowered blood glucose levels to near normal in the ob/ob and db/db mouse and fa/fa rat [149-151], These rodent models are homozygous for the indicated gene and are characterized by obesity, hyperglycemia, and hyperinsulinemia [12]. The ob allele is the gene for leptin, whereas db and fa are the genes for the leptin receptor in the mouse and rat, respectively. Leptin is one of the cytokine hormones that are produced in fat cells and act on receptors in the central nervous system. Its effects involve inhibition of food intake and promotion of energy expenditure [99],... 

Liposomes have received considerable attention as a possible delivery tool for peptide and protein drugs by protecting labile compounds from degradation or by enhancing the uptake of poorly absorbed compounds. Liposomes have been studied extensively as a potential oral delivery system for proteins, especially insulin, and the oral administration of liposome-entrapped insulin into diabetic rats has produced a significant fall in blood glucose levels. " There are three types of liposomes multilamellar liposomes (MLV), 0.05-10 pm small unilamellar liposomes (SUV),... 

Fatty acids are synthesized by an extramitochondrial system, which is responsible for the complete synthesis of palmitate from acetyl-CoA in the cytosol. In the rat, the pathway is well represented in adipose tissue and liver, whereas in humans adipose tissue may not be an important site, and liver has only low activity. In birds, lipogenesis is confined to the liver, where it is particularly important in providing lipids for egg formation. In most mammals, glucose is the primary substrate for lipogenesis, but in ruminants it is acetate, the main fuel molecule produced by the diet. Critical diseases of the pathway have not been reported in humans. However, inhibition of lipogenesis occurs in type 1 (insulin-de-pendent) diabetes mellitus, and variations in its activity may affect the nature and extent of obesity. 

The closed-loop type artificial pancreas (specifically 8-cell), which consists of an automatic continuous monitor of blood glucose level (BGL) and an automatic injector of insulin which are coupled with feed-back system, has great potential for prevention of diabetic complication such as micro-angiopathies(l). A large-scale closed-loop type artificial pancreas for bedside use has already been developed and is clinically used at some laboratories and hospitals (2-4). However, this device is limited to only bedside use. On the other hand, the open-loop type artificial pancreas which consists of only a insulin injecting pump without an automatic continuous monitor of BGL, has been developed and is going to be clinically used(5-7). This system, however, can not completely control BGL as well as the bare pancreas in a normal body and often causes lower BGL(8-9). 

It appears that insulin and certain growth factors may exert their effects by acting through this type of tyrosine kinase receptor-enzyme system.21,44 Insulin, for example, binds to the extracellular component of a protein located on skeletal muscle cells, thereby initiating activation of this protein s enzymatic activity on the inner surface of the cell membrane. This change in enzyme function causes further changes in cell activity, which ultimately result in increased glucose uptake in the muscle cell. The function of insulin receptors and their role in the cause and treatment of diabetes mellitus are discussed in more detail in Chapter 32. 

In the past, the main focus has been on insulin s effect on glucose uptake and hepatic glucose production. It now appears that there are many more players. The fate of glucose - or G6P - after uptake appears to be even more important for glucose metabolism, both in healthy persons and in patients with diabetes. There is an intimate interplay between the nutrient stores and between the different organs. This interplay appears well controlled, but the control is dynamic, so the detailed setup of the control system varies with the amount and type of nutrients. In this way the system can cope with almost any eating habit. 

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