Manganese glucose metabolism

The effect of GTF and chromium was further brought into question by the study of Shepherd et al. [32). These investigators found that potentiation of the action of suboptimal concentrations of insulin by GTF is more pronounced in adipocytes from rats fed a tomla yeast diet than in rats fed other diets differing only in the protein source. The authors conclude that the diets did not differ in amino acids, GTF active material, chromium, or 21 other trace elements measured in the diets. However, the level of manganese was low in all the diets, particularly in the torula yeast diet. Since manganese deficiencies have previously been implicated in abnormal glucose metabolism, this deficiency could be responsible for these effects. 

Manganese is involved in carbohydrate, lipid and protein metabolism and is required for the synthesis of glycoproteins and mucopolysaccharides such as hyaluronic add. It is also involved in glucose metabolism. In plants, it is involved in the enzyme that splits water into oxygen and hydrogen. 

Figure 5.4 Changes in certain allosteric enzyme sensitivities of A. n er in citric acid produdng mode compared to general metabolism. Conditions required for citric add accumulation manganese deficiency ferrous ion deficiency low pH high concentration of glucose.

Manganese deficiency can lead to several diseases including osteoporosis, epilepsy, impaired growth, poor bone formation and skeletal defects, abnormal glucose tolerance, and altered lipid and carbohydrate metabolism (Aschner and Aschner, 2005 Nkwenkeu et ah, 2002). 

Manganese. This element is required for blood clotting, carbohydrate metabolism, and as a component of various enzymes. Studies have shown that animals deficient in manganese have abnormal metabolism of glucose (a simple sugar), a defect which is corrected by manganese supplementation. ... 

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