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Query: UMLS:C0022672 (acute tubular necrosis)
 2,175 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism by which amino acid infusion stimulates membrane physpholipid biosynthesis during renal regeneration after mercuric-chloride-induced acute tubular necrosis was studied in the rat. Amino acids can act directly on regenerating renal tissue to enhance net phospholipid synthesis because preincubation of cortical slices with amino acids induced an increase in [14C]-choline incorporation into phospholipid without altering the rate of breakdown. This amino acid stimulation of phospholipid biosynthesis was studied further by measuring [14C]-choline accumulation and its sequential conversion to phosphorylcholine, cytidine diphosphocholine (CDP-choline), and phosphatidylcholine via the Kennedy pathway in regenerating renal tissue. [14C]-Choline accumulation was increased after amino acid infusion, compared to glucose infusion. There were also increments in the Vmax of the choline kinase reaction, which converts entering [14C]-choline into [14C]-phosphorylcholine, and of the cholinephosphotransferase reaction in which [14C]-CDP-choline is incorporated into [14C]-phosphatidylcholine, whereas the apparent Km of each reaction was unchanged. Thus, amino acids infused after tubular necrosis can act directly on regenerating renal cells to increase precursor availability and augment two reactions of the phospholipid biosynthetic pathway.
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PMID:Amino acid-mediated stimulation of renal phospholipid biosynthesis after acute tubular necrosis. 48 Jul 86

Phosphatidylcholine, the most abundant phospholipid in renal cellular membranes, is synthesized predominantly via the Kennedy pathway in normal and growing kidney tissue. Augmented biosynthesis of phosphatidylcholine is one of the earliest responses to growth signals in renal cells. During potassium depletion, regeneration after acute tubular necrosis, and compensatory growth after uninephrectomy increased membrane phosphatidylcholine biosynthesis precedes the appearance of new organelles and surface structures and the onset of cell division. The increment in phosphatidylcholine biosynthesis in the growing kidneys of potassium-depleted rats appears to be mediated by enhanced cellular uptake of the precursor choline and activation of the enzyme cytidine diphosphocholine:1,2-diacylglycerol cholinephosphotransferase. Specific amino acids, cations, and polyamines can modify the activity of this microsomal enzyme in normal and growing renal cells. Phospholipase A also plays a regulatory role in phosphatidylcholine metabolism because inhibition of this catabolic enzyme favors phospholipid accretion and kidney growth during potassium depletion, whereas stimulation of the enzyme leads to brisk phospholipid breakdown and a decrease in tissue mass during potassium repletion.
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PMID:Phosphatidylcholine metabolism during renal growth and regeneration. 636 86