Animal tissues, carbohydrate synthesis

The GM2 ganglioside (14) is an example of a carbohydrate antigen, specific for melanoma, sarcoma and kidney carcinoma. It could suit the purpose of an immuno therapy with monoclonal antibodies. In previous examinations the used GM2 was extracted from human and animal tissues. In this, one ran the risk of biological contamination of the GM2, which could influence the results of an examination. For this reason R. R. Schmidt et al. developed a total synthesis of the GM2 ganglioside to sustain sufficient substance for further immunological examinations without faking artifacts. ... 

Citric acid is a major end product of the oxidative metabolism of carbohydrate, ethanol, and acetic acid in many molds, e.g., Aspergillus niger. Evidence of the mechanism of citric acid formation is incomplete but the existing data are compatible with the assumption that citric acid arises, as an animal tissue, by condensation of oxalacetate with active acetic acid, as first proposed by Raistrick and Clark. Experiments with isotopic CO2 on Aspergillus suggest that the oxalacetate required for the synthesis of citrate can be formed by the carboxylation of pyruvate formed as an intermediate in the anaerobic fermentation.It is very... 

In animals, net triacylglycerol synthesis occurs when energy demands exceed immediate requirements. Most diets contain both fat and carbohydrates, but when there is a preponderance of energy as carbohydrates, the tissues convert them into fatty acids which are then esterified into acylglycerols. When there is a preponderance of fat in the diet, fat synthesis from carbohydrate is depressed in the tissues. The products of fat digestion are then converted into lipoproteins (section 5.3) which circulate in the bloodstream. When the lipoproteins reach the tissues, fatty acids are released from the acylglycerols at the endothelial surfaces of cells, a process catalysed by the enzyme lipoprotein lipase, and are taken up into the cells... 

Potassium [7440-09-7] K, is the third, element ia the aLkaU metal series. The name designation for the element is derived from potash, a potassium mineral the symbol from the German name kalium, which comes from the Arabic qili, a plant. The ashes of these plants al qili) were the historical source of potash for preparing fertilisers (qv) or gun powder. Potassium ions, essential to plants and animals, play a key role in carbohydrate metaboHsm in plants. In animals, potassium ions promote glycolysis, Hpolysis, tissue respiration, and the synthesis of proteins (qv) and acetylcholine. Potassium ions are also beheved to function in regulating blood pressure. 

Biotin forms part of several enzyme systems and is necessary for normal growth and body function. Biotin functions as a cofactor for enzymes involved in carbon dioxide fixation and transfer. These reactions are important in the metaboHsm of carbohydrates, fats, and proteins, as well as promotion of the synthesis and formation of nicotinic acid, fatty acids, glycogen, and amino acids (5—7). Biotin is absorbed unchanged in the upper part of the small intestine and distributed to all tissues. Highest concentrations are found in the Hver and kidneys. Little information is available on the transport and storage of biotin in humans or animals. A biotin level in urine of approximately 160 nmol/24 h or 70 nmol/L, and a circulating level in blood, plasma, or serum of approximately 1500 pmol/L seems to indicate an adequate supply of biotin for humans. However, reported levels for biotin in the blood and urine vary widely and are not a reHable indicator of nutritional status. 

The RQ for the conversion of glucose to fatty acids can be calculated from the biochemical considerations presented so far. This RQ would not be expected to occur in any living tissue or in any animal, because this RQ represents an extreme case in which there is no oxidation of fatty acids or of carbohydrates in the Krebs cycle. Where the rate of fatty acid synthesis is equal to the rate of fatty acid oxidation, the RQ would be expected to be 10. Where the rate of fatty acid synthesis is twice as great as the rate of fatty acid oxidation, the RQ would be greater than 1.0. One would not, however, expect to encounter a tissue in which there is only fatty acid synthesis and no fatty acid oxidation. 

Use Rapid determination of sugar in body fluids, and of animal starch in liver tissue general reagent for carbohydrates organic synthesis. 

There are several reports of patients with sucrosuria not related to dietary intake (Bl, El, H5, Rl, R3). This is quite surprising, for sucrose is considered to be produced only by plants no one has yet demonstrated sucrose synthesis by mammalian tissue. All of the reported patients with endogenous sucrosuria have shown this abnormality following pancreatic disease. Subacute pancreatitis, produced by instillation of turpentine into the pancreatic duct of animals, was followed by the appearance of readily detectable amounts of nonreducing, hydrolyzable carbohydrate in the urine within 24 hours whereas a similar injection into the common duct had no such effect. Chronic pancreatitis produced by passing a silk thread into the duct of Wirsung caused an increase in sucrose in the urine which disappeared if the pancreas was subsequently excised. Partial pancreatectomy is said to result in sucrosuria (Rl). 

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