Choline metabolism

Effects on Choline Metabolism THA has been reported to increase ACh brain levels. 

Wurtman, R.J. (1992) Choline metabolism as a basis for the selective vulnerability of cholinergic neurons. Trends Neurosci. 15 117-122. 

Wecker, L. 1986. Relationship between or gano-phosphate toxicity and choline metabolism. Govt. Rep. Announce. Index (U.S.) 89(11), Abstr. No. 930, p. 597 cited in Chem. Abstr. CA 111(11) 148458m. 

A controversial family of drugs at present, the selective serotonin reuptake inhibitors (SSRI, implicated in childhood suicide) have been followed using MRI to study choline metabolic rates . A common characteristic consistently revealed by MRS studies in cancer cells and solid tumours is the elevation of phosphatidyl choline and total choline-containing compounds - a possible target for early detection and therapy ... 

Green leafy materials, yeast, egg yolk and cereals are rich sources of choline. Metabolism... 

Gyorgi et at. (1947, 1949) reported that estrogens decrease the need for choline in rats. On the other hand, it is suggested that choline metabolism is increased in pregnancy, and choline seems to be necessary in the production of estrogens. A decreased oxidation of fatty acids is observed in choline deficiency. 

Plagemann, P. G. W. Cleaveland, P. H., and Shea, M. A., 1970, Effect of mengovirus replication on choline metabolism and membrane formation in Novikoff hepatoma cells, J. Virol. 6 800. 

The effect of prostaglandin F2a on arachidonate and lipid-choline metabolism in rat brain slices in vitro, in "Advances in Prostaglandin and Thromboxane Research", vol.3, G.GalU, C, Galli, and G.Porcellati, eds Raven Press, New York (1978). 

Bhakoo KK, Williams SR, Florian CL, Land H and Noble MD (1996) Immortalization and transformation are associated with specific alterations in choline metabolism. Cancer Research 56 4630-4635. 

Figure 6.1 Synthesis and metabolism of acetylcholine. Choline is acetylated by reacting with acetyl-CoA in the presence of choline acetyltransferase to form acetylcholine (1). The acetylcholine binds to the anionic site of cholinesterase and reacts with the hydroxy group of serine on the esteratic site of the enzyme (2). The cholinesterase thus becomes acetylated and choline splits off to be taken back into the nerve terminal for further ACh synthesis (3). The acetylated enzyme is then rapidly hydrolised back to its active state with the formation of acetic acid (4)...

King GM (1984) Metabolism of trimethylamine, choline and glycine betaine by sulfate-reducing and metha-nogenic bacteria in marine sediments. Appl Environ Microbiol 48 719-725. 

De Leo, V.A., Scheide, S., Meshulam, J., Hanson, D. and Cardulla, A. (1988). Ultraviolet radiation alters choline phospholipid metabolism in human keratinocytes. J. Invest. Dermatol. 91, 303-308. 

Detection by LDMS and structural elucidation of other secondary metabolite products, generated in the host during the onset of the parasite disease, is discussed. These molecules may serve as additional biomarkers for rapid malaria diagnosis by LDMS. For instance, choline phosphate (CP) is identified as the source of several low-mass ions observed in parasite-infected blood samples in addition to heme biomarker ions. The CP levels track the sample parasitemia levels. This biomarker can provide additional specificity and sensitivity when compared to malaria detection based on heme ion signals alone. Furthermore the observed elevated CP levels are discussed in the context of Plasmodium metabolism during its intra-erythrocytic life cycle. These data can... 

The primary mechanism used by cholinergic synapses is enzymatic degradation. Acetylcholinesterase hydrolyzes acetylcholine to its components choline and acetate it is one of the fastest acting enzymes in the body and acetylcholine removal occurs in less than 1 msec. The most important mechanism for removal of norepinephrine from the neuroeffector junction is the reuptake of this neurotransmitter into the sympathetic neuron that released it. Norepinephrine may then be metabolized intraneuronally by monoamine oxidase (MAO). The circulating catecholamines — epinephrine and norepinephrine — are inactivated by catechol-O-methyltransferase (COMT) in the liver. 

Arevalo, J.I. and Saz, H.J. (1992) Effects of cholinergic agents on the metabolism of choline in muscle from Ascaris suum. Journal of Parasitology 78, 387-392. 

Choline is supplied to the neuron either from plasma or by metabolism of choline-containing compounds 193 A slow release of acetylcholine from neurons at rest probably occurs at all cholinergic synapses 194 The relationship between acetylcholine content in a vesicle and the quanta of acetylcholine released can only be estimated 194 Depolarization of the nerve terminal by an action potential increases the number of quanta released per unit time 194 All the acetylcholine contained within the cholinergic neuron does not behave as if in a single compartment 194... 

Choline is supplied to the neuron either from plasma or by metabolism of choline-containing compounds. The... 

Membrane/lipid metabolism/ choline/glycerophosphorylcholine/ Cho/ PCho GPCho/... 

The contribution of pseudocholinesterase, also known simply as cholinesterase, to drug metabolism is much greater as it possesses considerably broader substrate selectivity. In addition to acetylcholine, it will hydrolyze other choline esters like the muscle relaxant succinylcholine. It will also hydrolyze non-choline-containing drugs like the local anesthetic procaine and the anti-inflammatory agent aspirin (Fig. 6.5). Cholinesterases, particularly... 

Thus a distinction was provided between simple esterases, such as fiver esterase, which catalysed the hydrolysis of simple aliphatic esters but were ineffective towards choline esters. The term 1 cholinesterase was extended to other enzymes, present in blood sera and erythrocytes of other animals, including man, and in nervous tissue, which catalysed the hydrolysis of acetylcholine. It was assumed that only one enzyme was involved until Alles and Hawes2 found that the enzyme present in human erythrocytes readily catalysed the hydrolysis of acetylcholine, but was inactive towards butyrylcholine. Human-serum enzyme, on the other hand, hydrolyses butyrylcholine more rapidly than acetylcholine. The erythrocyte enzyme is sometimes called true cholinesterase, whereas the serum enzyme is sometimes called pseudo-cholinesterase. Stedman,3 however, prefers the names a-cholinesterase for the enzyme more active towards acetylcholine, and / -cholinesterase for the one preferentially hydrolysing butyrylcholine. Enzymes of the first type play a fundamental part in acetylcholine metabolism in vivo. The function of the second type in vivo is obscure. Not everyone agrees with the designation suggested by Stedman. It must also be stressed that enzymes of one type from different species are not always identical in every respect.4 Furthermore,... 

Ginkgo alters lipid metabolism created by electroconvulsive shock treatments. EGb 761 reduced accumulation of free fatty acids and removal of diacylglycerol, which is more pronounced in the hippocampus than cerebral cortex (Rodriguez de Turco et al. 1993). Ginkgo also has protective effects on lipid membranes under hypoxic conditions. Bilobalide, but not ginkgolides, suppressed hydrolysis of choline induced... 

As with all the major transmitters, acetylcholine is stored in vesicles within the nerve terminal from which it is released by a calcium-dependent mechanism following the passage of a nerve impulse. The inter-relationship between the intermediary metabolism of glucose, phospholipids and the uptake of choline is summarized in Figure 2.14. 

Orotic acid added to rat diet also provokes an. excessive biosynthesis of porphyrins in liver, erythrocytes and bone marrow. Administration of adenine monophosphate (AMP) counteracted this effect of orotic acid intoxication [165]. Haemorrhagic renal necrosis in rats, caused by choline deficiency, can be relieved by orotic acid [166], Simultaneous supplementation of the diet with adenine does not influence the protective effect of orotic acid. It has been suggested that orotic acid may lower the body requirement for choline through a metabolic interaction—orotic acid may stimulate the cytidine phosphate choline pathway of lecthin biosynthesis [166]. 

Fluoro-choline (p F]-FCH) Cell membrane metabolism Oncology... 

In the human body choline is needed for the synthesis of phospholipids in cell membranes, methyl metabolism, transmembrane signaling and lipid cholesterol transport and metabolism [169]. It is transported into mammalian cells by a high-affinity sodium-dependent transport system. Intracellular choline is metabolized to phosphorylcholine, the reaction being catalyzed by the enzyme choline... 

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