English Journal
- Pharmacological enhancement of leg and muscle microvascular blood flow does not augment anabolic responses in skeletal muscle of young men under fed conditions.
- Phillips BE1, Atherton PJ, Varadhan K, Wilkinson DJ, Limb M, Selby AL, Rennie MJ, Smith K, Williams JP.Author information 1Division of Medical Science and Graduate Entry Medicine, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom; and.AbstractSkeletal muscle anabolism associated with postprandial plasma aminoacidemia and insulinemia is contingent upon amino acids (AA) and insulin crossing the microcirculation-myocyte interface. In this study, we hypothesized that increasing muscle microvascular blood volume (flow) would enhance fed-state anabolic responses in muscle protein turnover. We studied 10 young men (23.2 ± 2.1 yr) under postabsorptive and fed [iv Glamin (∼10 g AA), glucose ∼7.5 mmol/l] conditions. Methacholine was infused into the femoral artery of one leg to determine, via bilateral comparison, the effects of feeding alone vs. feeding plus pharmacological vasodilation. We measured leg blood flow (LBF; femoral artery) by Doppler ultrasound, muscle microvascular blood volume (MBV) by contrast-enhanced ultrasound (CEUS), muscle protein synthesis (MPS) and breakdown (MPB; a-v balance modeling), and net protein balance (NPB) using [1,2-(13)C2]leucine and [(2)H5]phenylalanine tracers via gas chromatography-mass spectrometry (GC-MS). Indexes of anabolic signaling/endothelial activation (e.g., Akt/mTORC1/NOS) were assessed using immunoblotting techniques. Under fed conditions, LBF (+12 ± 5%, P < 0.05), MBV (+25 ± 10%, P < 0.05), and MPS (+129 ± 33%, P < 0.05) increased. Infusion of methacholine further enhanced LBF (+126 ± 12%, P < 0.05) and MBV (+79 ± 30%, P < 0.05). Despite these radically different blood flow conditions, neither increases in MPS in response to feeding (0.04 ± 0.004 vs. 0.08 ± 0.01%/h, P < 0.05) nor improvements in NPB (-4.4 ± 2.4 vs. 16.4 ± 5.7 nmol Phe·100 ml leg(-1)·min(-1), P < 0.05) were affected by methacholine infusion (MPS 0.07 ± 0.01%/h; NPB 24.0 ± 7.7 nmol Phe·100 ml leg(-1)·min(-1)), whereas MPB was unaltered by either feeding or infusion of methacholine. Thus, enhancing LBF/MBV above that occurring naturally with feeding alone does not improve muscle anabolism.
- American journal of physiology. Endocrinology and metabolism.Am J Physiol Endocrinol Metab.2014 Jan 15;306(2):E168-76. doi: 10.1152/ajpendo.00440.2013. Epub 2013 Nov 26.
- Skeletal muscle anabolism associated with postprandial plasma aminoacidemia and insulinemia is contingent upon amino acids (AA) and insulin crossing the microcirculation-myocyte interface. In this study, we hypothesized that increasing muscle microvascular blood volume (flow) would enhance fed-state
- PMID 24280127
- Alloisoleucine differentiates the branched-chain aminoacidemia of Zucker and dietary obese rats.
- Olson KC1, Chen G, Xu Y, Hajnal A, Lynch CJ.Author information 1Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, Pennsylvania, USA.AbstractOBJECTIVE: Circulating branched-chain amino acids (BCAAs) are elevated in obesity and this has been linked to obesity comorbidities. However it is unclear how obesity affects alloisoleucine, a BCAA and pathognomonic marker of branched-chain keto acid dehydrogenase complex (BCKDC) disorders. It has been previously established that obese Zucker rats exhibit BCKDC impairments in fat and other tissues, whereas BCKDC impairments in adipose tissue of DIO rats are compensated by increased hepatic BCKDC activity. Therefore, alloisoleucine was investigated in these two obesity models.
- Obesity (Silver Spring, Md.).Obesity (Silver Spring).2014 Jan 11. doi: 10.1002/oby.20691. [Epub ahead of print]
- OBJECTIVE: Circulating branched-chain amino acids (BCAAs) are elevated in obesity and this has been linked to obesity comorbidities. However it is unclear how obesity affects alloisoleucine, a BCAA and pathognomonic marker of branched-chain keto acid dehydrogenase complex (BCKDC) disorders. It has b
- PMID 24415721
- Side effects of long-term glutamine supplementation.
- Holecek M.Author information Department of Physiology, Charles University in Prague, Faculty of Medicine in Hradec Kralove, Simkova 870, 500 38 Hradec Kralove, Czech Republic. holecek@lfhk.cuni.czAbstractSome people consume chronically glutamine (GLN) in high quantities (~40 g/d), although a number of biochemical pathways and cellular functions may be negatively affected. The following side effects of GLN supplementation are discussed: (1) Alterations in amino acid transport-as GLN shares the transporters with other amino acids, enhanced GLN intake may impair amino acid distribution among tissues and their absorption in the gut and kidneys. (2) Alterations in GLN metabolism-GLN supplementation may impair synthesis of endogenous GLN and enhance glutamate and ammonia production. (3) Alterations in ammonia transport-GLN supplementation may impair ammonia detoxification and negatively affect the role of GLN as the carrier of ammonia among tissues. (4) Abnormalities in aminoacidemia-increased plasma levels of GLN, glutamate, citrulline, ornithine, arginine, and histidine and decreased levels of valine, leucine, isoleucine, glycine, threonine, serine, and proline are reported. (5) Alterations in immune system-as GLN has immunomodulating properties, the effect of chronic GLN consumption on the immune system needs to be assessed. (6) Effect on tumor growth-it should be elucidated whether chronic intake of GLN increases the risk of cancer. (7) Effect of the withdrawal of GLN supplementation-due to the adaptive response of the organism to enhanced GLN consumption, the withdrawal of GLN may enhance the risk of health problems resulting from GLN deficiency. It is concluded that enhanced intake of GLN has substantial side effects, and long-term studies should be performed to justify chronic consumption of a GLN-enriched diet.
- JPEN. Journal of parenteral and enteral nutrition.JPEN J Parenter Enteral Nutr.2013 Sep;37(5):607-16. doi: 10.1177/0148607112460682. Epub 2012 Sep 18.
- Some people consume chronically glutamine (GLN) in high quantities (~40 g/d), although a number of biochemical pathways and cellular functions may be negatively affected. The following side effects of GLN supplementation are discussed: (1) Alterations in amino acid transport-as GLN shares the transp
- PMID 22990615
Japanese Journal
- The mutation spectrum of the SLC25A13 gene in Chinese infants with intrahepatic cholestasis and aminoacidemia
- FU Hai-Yan,ZHANG Shao-Ren,WANG Xiao-Hong,SAHEKI Takeyori,KOBAYASHI Keiko,WANG Jian-She
- Journal of gastroenterology 46(4), 510-518, 2011-04-01
- NAID 10029028662
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- aminoacidemia a·mi·no·ac·i·de·mi·a (ə-mē'nō-ās'ĭ-dē'mē-ə, ām'ə-nō-) n. An excess of specific amino acids in the blood.
- aminoacidemia /ami·no·ac·id·emia/ (ah-me″no-as″ĭ-de´me-ah) an excess of amino acids in the blood. a·mi·no·ac·i·de·mi·a (ə-mē′nō-ăs′ĭ-dē′mē-ə, ăm′ə-nō-) n. An excess of specific amino acids in the blood. aminoacidemia [ah-me″no ...
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