Carbohydrate homeostasis

Carbohydrate is essential for the survival of some tissues and as a structural constituent of nucleic acids, glycoproteins, proteoglycans, and glycolipids. The normal adult can synthesize all the needed carbohydrate from noncarbohydrate sources, namely, amino acids and glycerol. Thus, 

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Toxicity. Atractyloside, a diterpenoid glycoside that occurs naturally in plants, may be present at levels as high as 600 mg/kg of dried plant material. Gonsumption of plants containing atractyloside or carboxyatractyl-oside has caused fatal renal proximal tubule necrosis and/or centrilobular hepatic necrosis in man and farm animals. Although pure atractyloside and crude plant extracts disrupt carbohydrate homeostasis and induce similar pathophysiological lesions in the kidney and liver, it is also possible that the toxicity of atractyloside may be confounded by the presence of other natural constituents in plants. Atractyloside competitively inhibits the adenine nucleoside... 

Since changes in glucose balance after diuretics tend to be reversible on withdrawal, measures of carbohydrate homeostasis should be assessed after several months of thiazide treatment to detect those few patients who experience significant glucose intolerance (353). With this approach, the small risk of diabetes mellitus secondary to diuretic therapy can be minimized. 

Compare the hormonal changes that occur at birth and their effects on carbohydrate homeostasis with those that occur in adults during starvation. 

The effect of manganese deficiency or excess on carbohydrate homeostasis have been studied by Keen, Hmley and coworkers, with some focus on pyruvate carboxylase and PEP carboxykinase [302-304]. Other evidence indicates that Mn(II) has an insulin-mimetic effect, acting to stimulate protein kinases or phosphatases that control enzymes involved in glycolysis, gluconeogenesis, or the hexose mono-P pathway [305-307]. A key role of Mn(II) in mucopolysaccharide metabolism has long been recognized [6]. 

TrostBN, WeidmannP. 5 years of antihypertensive monotherapy with the calcium antagonist nitrendipine do not alter carbohydrate homeostasis in diabetic patients. Diabetes Res Clin Pract( m) 5 (Suppl 1), S511. 

O Signs and symptoms of adrenal insufficiency reflect the disturbance of normal physiologic carbohydrate, fat, and protein homeostasis caused by inadequate cortisol production and inadequate cortisol action. 

Cortisol An adrenal gland hormone responsible for maintaining homeostasis of carbohydrate, protein, and fat metabolism. 

The liver not only extracts glucose from the blood in the postprandial state and stores it as glycogen, but is also able to synthesize glucose from non-carbohydrate sources via gluconeogenesis, therefore the liver is crucial in regulating glucose homeostasis. 

Acting as an intracellular second messenger, cAMP mediates such hormonal responses as the mobilization of stored energy (the breakdown of carbohydrates in liver or triglycerides in fat cells stimulated by B-adrenomimetic catecholamines), conservation of water by the kidney (mediated by vasopressin), Ca2+ homeostasis (regulated by parathyroid hormone), and increased rate and contractile force of heart muscle ( -adrenomimetic catecholamines). It also regulates the production of adrenal and sex steroids (in response to corticotropin or follicle-stimulating hormone), relaxation of smooth muscle, and many other endocrine and neural processes. 

Insulin is a storage hormone produced by the pancreas. Insulin shuttles nutrients, such as carbohydrates, fats and amino acids (derived from proteins) into cells. The main function of insulin is to maintain homeostasis of circulatory glucose, and intracellular glycogen storage. It also aids in fat storage. 

Other strategies include detailed studies of the changes in brain carbohydrate metabolism in ageing and how this may differ in patients with Alzheimer s disease. Changes in the composition and biophysical properties of neuronal membranes may also be of crucial importance in regulating the cytosolic free calcium, which could affect cellular homeostasis. 

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