James M. May, M.D.

Professor

james.may@vanderbilt.edu

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Faculty Appointments
Professor of Medicine Professor of Molecular Physiology and Biophysics
Education
M.D., Medicine, Vanderbilt University, Nashville, TennesseeB.S., Biology, Yale University, New Haven, Connecticut
Office Address
7465 MRB IV
2213 Garland Ave
Nashville, TN 37232-0475
Research Description
Dr. May's laboratory is involved in three major areas involving antioxidant vitamins and micronutrients: the function of vitamin C in atherosclerosis; study of the role of vitamin C in protection against the oxidant stress of Alzheimer's disease, and study of the antioxidant interactions of selenium and vitamins C and E.

Dr. May's research interests invove the antioxidant effects of vitamins C and E in a variety of cell and animal models. His laboratory has long been active in the study of how vitamin C is taken up, maintained in a reduced form, and how it protects cells against oxidant stress. In the last several years, the effort has targeted the early stages of atherosclerosis, especially related to endothelial dysfunction and the ability of the vitamin to enhance release and function of nitric oxide. More recently, efforts have turned to testing whether the vitamin also plays a role in inhibiting the atherosclerotic process in other cells, including macrophages and vascular smooth muscle cells. The central hypothesis in this work is that the vitamin C transporter is crucial for maintaining high intracellular concentrations of this vitamin. Other functions of vitamin C besides those related to antioxidant mechanisms are also explored, including its role in cell proliferation, differentiation, and collagen formation.

Alzheimer's disease is associated with oxidant stress, and vitamin C has been implicated in clinical studies in protecting against this stress and in slowing progression of the disease. Studies are underway to assess the role of the vitamin in beta-amyloid secretion and action by cultured neuronal cells, and to asses whether dietary manipulation with vitamin C in normal mice and mice unable to synthesize the vitamin can slow the progression of the behavioral changes seen in animals transgenic for amyloid precursor protein and presenilin 1. Both of these proteins are implicated in many patients with Alzheimer's disease.

Selenium is a co-factor for several enzymes with antioxidant function, including glutathione peroxidase and thioredoxin reductase. Dr. May's laboratory showed that the latter enzyme can reduce the oxidized forms of vitamin C back to the reduced form. The ability of this selenoenzyme to recycle vitamin C may provide a missing link between the known ability of vitamin E or selenium to mitigate a deficiency in the other. In cultured cells and in guinea pigs (which can be made deficient in all three factors), studies are underway of the interactions between these factors with regard to cellular metabolism and lipid peroxidation. The approaches used in these studies include HPLC assays of antioxidants, enzyme assays, and assays of lipid peroxidation.
Research Keywords
Antioxidants, Vitamin C, Vitamin E, Selecum, Oxidant Stress,Glucose Trasport, Insulin Action, Hexokinase
Publications
Pierce MR, Raj A, Betke KM, Zeidan LN, Matthies HJ, May JM. Sodium-dependent vitamin C transporter-2 mediates vitamin C transport at the cortical nerve terminal. J. Neurosci. Res [print-electronic]. 2015 Dec; 93(12): 1881-90. PMID: 26366722, PMCID: PMC4618169, DOI: 10.1002/jnr.23669, ISSN: 1097-4547.

May JM, Qu ZC. Ascorbic acid efflux from human brain microvascular pericytes: Role of re-uptake. Biofactors [print-electronic]. 2015 Sep 9/10/2015; 41(5): 330-8. PMID: 26340060, PMCID: PMC4624047, DOI: 10.1002/biof.1227, ISSN: 1872-8081.

Parker WH, Qu ZC, May JM. Intracellular Ascorbate Prevents Endothelial Barrier Permeabilization by Thrombin. J. Biol. Chem [print-electronic]. 2015 Aug 8/28/2015; 290(35): 21486-97. PMID: 26152729, PMCID: PMC4571875, PII: M115.662098, DOI: 10.1074/jbc.M115.662098, ISSN: 1083-351X.

Parker WH, Qu ZC, May JM. Ascorbic acid transport in brain microvascular pericytes. Biochem. Biophys. Res. Commun [print-electronic]. 2015 Mar 3/6/2015; 458(2): 262-7. PMID: 25645015, PMCID: PMC4351875, PII: S0006-291X(15)00135-7, DOI: 10.1016/j.bbrc.2015.01.096, ISSN: 1090-2104.

Babaev VR, Hebron KE, Wiese CB, Toth CL, Ding L, Zhang Y, May JM, Fazio S, Vickers KC, Linton MF. Macrophage deficiency of Akt2 reduces atherosclerosis in Ldlr null mice. J. Lipid Res [print-electronic]. 2014 Nov; 55(11): 2296-308. PMID: 25240046, PMCID: PMC4617132, PII: jlr.M050633, DOI: 10.1194/jlr.M050633, ISSN: 0022-2275.

May JM, Jayagopal A, Qu ZC, Parker WH. Ascorbic acid prevents high glucose-induced apoptosis in human brain pericytes. Biochem. Biophys. Res. Commun [print-electronic]. 2014 Sep 9/12/2014; 452(1): 112-7. PMID: 25152398, PMCID: PMC4167575, PII: S0006-291X(14)01480-6, DOI: 10.1016/j.bbrc.2014.08.057, ISSN: 1090-2104.

Meredith ME, Qu ZC, May JM. Ascorbate reverses high glucose- and RAGE-induced leak of the endothelial permeability barrier. Biochem. Biophys. Res. Commun [print-electronic]. 2014 Feb 2/28/2014; 445(1): 30-5. PMID: 24472555, PMCID: PMC3955275, PII: S0006-291X(14)00102-8, DOI: 10.1016/j.bbrc.2014.01.078, ISSN: 1090-2104.

May JM, Harrison FE. Role of vitamin C in the function of the vascular endothelium. Antioxid. Redox Signal [print-electronic]. 2013 Dec 12/10/2013; 19(17): 2068-83. PMID: 23581713, PMCID: PMC3869438, DOI: 10.1089/ars.2013.5205, ISSN: 1557-7716.

Meredith ME, May JM. Regulation of embryonic neurotransmitter and tyrosine hydroxylase protein levels by ascorbic acid. Brain Res [print-electronic]. 2013 Nov 11/20/2013; 1539: 7-14. PMID: 24095796, PMCID: PMC3849618, PII: S0006-8993(13)01314-0, DOI: 10.1016/j.brainres.2013.09.040, ISSN: 1872-6240.

Pierce MR, Diasio DL, Rodrigues LM, Harrison FE, May JM. Combined vitamin C and E deficiency induces motor defects in gulo(-/-)/SVCT2(+/-) mice. Nutr Neurosci [print-electronic]. 2013 Jul; 16(4): 160-73. PMID: 23321552, PMCID: PMC3869026, PII: nns109, DOI: 10.1179/1476830512Y.0000000042, ISSN: 1476-8305.

Ward MS, Lamb J, May JM, Harrison FE. Behavioral and monoamine changes following severe vitamin C deficiency. J. Neurochem [print-electronic]. 2013 Feb; 124(3): 363-75. PMID: 23106783, PMCID: PMC3540126, DOI: 10.1111/jnc.12069, ISSN: 1471-4159.

May JM, Qu ZC, Nazarewicz R, Dikalov S. Ascorbic acid efficiently enhances neuronal synthesis of norepinephrine from dopamine. Brain Res. Bull [print-electronic]. 2013 Jan; 90: 35-42. PMID: 23022576, PMCID: PMC3527656, PII: S0361-9230(12)00209-2, DOI: 10.1016/j.brainresbull.2012.09.009, ISSN: 1873-2747.

May JM, Qu ZC, Meredith ME. Mechanisms of ascorbic acid stimulation of norepinephrine synthesis in neuronal cells. Biochem. Biophys. Res. Commun [print-electronic]. 2012 Sep 9/14/2012; 426(1): 148-52. PMID: 22925890, PMCID: PMC3449284, PII: S0006-291X(12)01564-1, DOI: 10.1016/j.bbrc.2012.08.054, ISSN: 1090-2104.

Jiang H, Harrison FE, Jain K, Benjamin S, May JM, Graves JP, Zeldin DC, Falck JR, Hammock BD, McGiff JC. Vitamin C activation of the biosynthesis of epoxyeicosatrienoic acids. Adv Biosci Biotechnol. 2012 Jun 6/1/2012; 3(3): 204-18. PMID: 24660109, PMCID: PMC3958942, DOI: 10.4236/abb.2012.33029, ISSN: 2156-8456.

Harrison FE, Best JL, Meredith ME, Gamlin CR, Borza DB, May JM. Increased expression of SVCT2 in a new mouse model raises ascorbic acid in tissues and protects against paraquat-induced oxidative damage in lung. PLoS ONE [print-electronic]. 2012; 7(4): e35623. PMID: 22558179, PMCID: PMC3340390, PII: PONE-D-12-05229, DOI: 10.1371/journal.pone.0035623, ISSN: 1932-6203.

Qiao H, May JM. Interaction of the transcription start site core region and transcription factor YY1 determine ascorbate transporter SVCT2 exon 1a promoter activity. PLoS ONE [print-electronic]. 2012; 7(4): e35746. PMID: 22532872, PMCID: PMC3332055, PII: PONE-D-11-20186, DOI: 10.1371/journal.pone.0035746, ISSN: 1932-6203.

May JM. Vitamin C transport and its role in the central nervous system. Subcell. Biochem. 2012; 56: 85-103. PMID: 22116696, PMCID: PMC3725125, DOI: 10.1007/978-94-007-2199-9_6, ISSN: 0306-0225.

May JM. The SLC23 family of ascorbate transporters: ensuring that you get and keep your daily dose of vitamin C. Br. J. Pharmacol. 2011 Dec; 164(7): 1793-801. PMID: 21418192, PMCID: PMC3246704, DOI: 10.1111/j.1476-5381.2011.01350.x, ISSN: 1476-5381.

Qiao H, May JM. CpG methylation at the USF-binding site mediates cell-specific transcription of human ascorbate transporter SVCT2 exon 1a. Biochem. J. 2011 Nov 11/15/2011; 440(1): 73-84. PMID: 21770893, PMCID: PMC3709574, PII: BJ20110392, DOI: 10.1042/BJ20110392, ISSN: 1470-8728.

Meredith ME, Harrison FE, May JM. Differential regulation of the ascorbic acid transporter SVCT2 during development and in response to ascorbic acid depletion. Biochem. Biophys. Res. Commun [print-electronic]. 2011 Nov 11/4/2011; 414(4): 737-42. PMID: 22001929, PMCID: PMC3210393, PII: S0006-291X(11)01774-8, DOI: 10.1016/j.bbrc.2011.09.146, ISSN: 1090-2104.

Qiu S, Li L, Weeber EJ, May JM. Ascorbate transport by primary cultured neurons and its role in neuronal function and protection against excitotoxicity. J. Neurosci. Res. 2007 Apr; 85(5): 1046-56. PMID: 17304569, DOI: 10.1002/jnr.21204, ISSN: 0360-4012.

Huang J, May JM. Ascorbic acid protects SH-SY5Y neuroblastoma cells from apoptosis and death induced by beta-amyloid. Brain Res [print-electronic]. 2006 Jun 6/30/2006; 1097(1): 52-8. PMID: 16725131, PII: S0006-8993(06)01127-9, DOI: 10.1016/j.brainres.2006.04.047, ISSN: 0006-8993.

May JM, Qu ZC, Nelson DJ. Cellular disulfide-reducing capacity: an integrated measure of cell redox capacity. Biochem. Biophys. Res. Commun [print-electronic]. 2006 Jun 6/16/2006; 344(4): 1352-9. PMID: 16650819, PII: S0006-291X(06)00869-2, DOI: 10.1016/j.bbrc.2006.04.065, ISSN: 0006-291X.

May JM, Li L, Hayslett K, Qu ZC. Ascorbate transport and recycling by SH-SY5Y neuroblastoma cells: response to glutamate toxicity. Neurochem. Res [print-electronic]. 2006 Jun; 31(6): 785-94. PMID: 16791474, DOI: 10.1007/s11064-006-9077-z, ISSN: 0364-3190.

Burk RF, Christensen JM, Maguire MJ, Austin LM, Whetsell WO, May JM, Hill KE, Ebner FF. A combined deficiency of vitamins E and C causes severe central nervous system damage in guinea pigs. J. Nutr. 2006 Jun; 136(6): 1576-81. PMID: 16702324, PII: 136/6/1576, ISSN: 0022-3166.

May JM, Huang J, Qu ZC. Macrophage uptake and recycling of ascorbic acid: response to activation by lipopolysaccharide. Free Radic. Biol. Med [print-electronic]. 2005 Dec 12/1/2005; 39(11): 1449-59. PMID: 16274880, PII: S0891-5849(05)00393-X, DOI: 10.1016/j.freeradbiomed.2005.07.006, ISSN: 0891-5849.

May JM, Li L, Qu ZC, Huang J. Ascorbate uptake and antioxidant function in peritoneal macrophages. Arch. Biochem. Biophys. 2005 Aug 8/15/2005; 440(2): 165-72. PMID: 16054587, PII: S0003-9861(05)00262-6, DOI: 10.1016/j.abb.2005.06.018, ISSN: 0003-9861.

May JM, Qu ZC, Juliao S, Cobb CE. Ascorbic acid decreases oxidant stress in endothelial cells caused by the nitroxide tempol. Free Radic. Res. 2005 Feb; 39(2): 195-202. PMID: 15763967, PII: JKQ36HM3D3NPQ9U0, DOI: 10.1080/10715760400019661, ISSN: 1071-5762.

May JM, Qu ZC. Transport and intracellular accumulation of vitamin C in endothelial cells: relevance to collagen synthesis. Arch. Biochem. Biophys. 2005 Feb 2/1/2005; 434(1): 178-86. PMID: 15629121, PII: S0003-9861(04)00615-0, DOI: 10.1016/j.abb.2004.10.023, ISSN: 0003-9861.

Huang J, de Paulis T, May JM. Antioxidant effects of dihydrocaffeic acid in human EA.hy926 endothelial cells. J. Nutr. Biochem. 2004 Dec; 15(12): 722-9. PMID: 15607645, PII: S0955-2863(04)00135-4, DOI: 10.1016/j.jnutbio.2004.07.002, ISSN: 0955-2863.

Steffner RJ, Wu L, Powers AC, May JM. Ascorbic acid recycling by cultured beta cells: effects of increased glucose metabolism. Free Radic. Biol. Med. 2004 Nov 11/15/2004; 37(10): 1612-21. PMID: 15477012, PII: S0891-5849(04)00608-2, DOI: 10.1016/j.freeradbiomed.2004.07.032, ISSN: 0891-5849.

May JM, Qu ZC. Nitric oxide-induced oxidant stress in endothelial cells: amelioration by ascorbic acid. Arch. Biochem. Biophys. 2004 Sep 9/1/2004; 429(1): 106-13. PMID: 15288814, PII: S0003986104003303, DOI: 10.1016/j.abb.2004.06.012, ISSN: 0003-9861.

May JM, Qu ZC, Li X. Nitrite generates an oxidant stress and increases nitric oxide in EA.hy926 endothelial cells. Free Radic. Res. 2004 Jun; 38(6): 581-9. PMID: 15346649, ISSN: 1071-5762.

May JM, Qu ZC, Cobb CE. Reduction and uptake of methylene blue by human erythrocytes. Am. J. Physiol., Cell Physiol [print-electronic]. 2004 Jun; 286(6): C1390-8. PMID: 14973146, PII: 00512.2003, DOI: 10.1152/ajpcell.00512.2003, ISSN: 0363-6143.

May JM, Qu ZC, Cobb CE. Human erythrocyte recycling of ascorbic acid: relative contributions from the ascorbate free radical and dehydroascorbic acid. J. Biol. Chem [print-electronic]. 2004 Apr 4/9/2004; 279(15): 14975-82. PMID: 14752116, PII: M312548200, DOI: 10.1074/jbc.M312548200, ISSN: 0021-9258.

Wu L, Nicholson W, Knobel SM, Steffner RJ, May JM, Piston DW, Powers AC. Oxidative stress is a mediator of glucose toxicity in insulin-secreting pancreatic islet cell lines. J. Biol. Chem [print-electronic]. 2004 Mar 3/26/2004; 279(13): 12126-34. PMID: 14688272, PII: M307097200, DOI: 10.1074/jbc.M307097200, ISSN: 0021-9258.

May JM, Qu ZC, Whitesell RR. Generation of oxidant stress in cultured endothelial cells by methylene blue: protective effects of glucose and ascorbic acid. Biochem. Pharmacol. 2003 Sep 9/1/2003; 66(5): 777-84. PMID: 12948858, PII: S0006295203004088, ISSN: 0006-2952.

Li X, May JM. Location and recycling of mitochondrial alpha-tocopherol. Mitochondrion. 2003 Aug; 3(1): 29-38. PMID: 16120342, PII: S1567-7249(03)00058-8, DOI: 10.1016/S1567-7249(03)00058-8, ISSN: 1567-7249.

Li X, Huang J, May JM. Ascorbic acid spares alpha-tocopherol and decreases lipid peroxidation in neuronal cells. Biochem. Biophys. Res. Commun. 2003 Jun 6/6/2003; 305(3): 656-61. PMID: 12763044, PII: S0006291X03008362, ISSN: 0006-291X.

Hill KE, Montine TJ, Motley AK, Li X, May JM, Burk RF. Combined deficiency of vitamins E and C causes paralysis and death in guinea pigs. Am. J. Clin. Nutr. 2003 Jun; 77(6): 1484-8. PMID: 12791628, ISSN: 0002-9165.

May JM, Qu ZC, Neel DR, Li X. Recycling of vitamin C from its oxidized forms by human endothelial cells. Biochim. Biophys. Acta. 2003 May 5/12/2003; 1640(2-3): 153-61. PMID: 12729925, PII: S0167488903000430, ISSN: 0006-3002.

Huang J, May JM. Ascorbic acid spares alpha-tocopherol and prevents lipid peroxidation in cultured H4IIE liver cells. Mol. Cell. Biochem. 2003 May; 247(1-2): 171-6. PMID: 12841645, ISSN: 0300-8177.

May JM, Qu ZC, Li X. Ascorbic acid blunts oxidant stress due to menadione in endothelial cells. Arch. Biochem. Biophys. 2003 Mar 3/1/2003; 411(1): 136-44. PMID: 12590932, PII: S0003986102007154, ISSN: 0003-9861.

Whitesell RR, Ardehali H, Printz RL, Beechem JM, Knobel SM, Piston DW, Granner DK, Van Der Meer W, Perriott LM, May JM. Control of glucose phosphorylation in L6 myotubes by compartmentalization, hexokinase, and glucose transport. Biochem. J. 2003 Feb 2/15/2003; 370(Pt 1): 47-56. PMID: 12410639, PMCID: PMC1223141, PII: BJ20021256, DOI: 10.1042/BJ20021256, ISSN: 0264-6021.

Jones W, Li X, Qu ZC, Perriott L, Whitesell RR, May JM. Uptake, recycling, and antioxidant actions of alpha-lipoic acid in endothelial cells. Free Radic. Biol. Med. 2002 Jul 7/1/2002; 33(1): 83-93. PMID: 12086686, PII: S0891584902008626, ISSN: 0891-5849.

Li X, Cobb CE, May JM. Mitochondrial recycling of ascorbic acid from dehydroascorbic acid: dependence on the electron transport chain. Arch. Biochem. Biophys. 2002 Jul 7/1/2002; 403(1): 103-10. PMID: 12061807, PII: S0003-9861(02)00205-9, DOI: 10.1016/S0003-9861(02)00205-9, ISSN: 0003-9861.

Li X, May JM. Catalase-dependent measurement of H2O2 in intact mitochondria. Mitochondrion. 2002 May; 1(5): 447-53. PMID: 16120297, PII: S1567-7249(02)00010-7, ISSN: 1567-7249.

May JM, Morrow JD, Burk RF. Thioredoxin reductase reduces lipid hydroperoxides and spares alpha-tocopherol. Biochem. Biophys. Res. Commun. 2002 Mar 3/22/2002; 292(1): 45-9. PMID: 11890669, PII: S0006291X02966179, ISSN: 0006-291X.

Hardy TA, May JM. Coordinate regulation of L-arginine uptake and nitric oxide synthase activity in cultured endothelial cells. Free Radic. Biol. Med. 2002 Jan 1/15/2002; 32(2): 122-31. PMID: 11796200, PII: S089158490100781X, ISSN: 0891-5849.

May JM. Recycling of vitamin C by mammalian thioredoxin reductase. Meth. Enzymol. 2002; 347: 327-32. PMID: 11898423, ISSN: 0076-6879.

May, J.M. Recycling of vitamin C by mammalian thioredoxin reductase. Methods Enzymol. 2002; 347: 327-32.

Li X, Qu ZC, May JM. GSH is required to recycle ascorbic acid in cultured liver cell lines. Antioxid. Redox Signal. 2001 Dec; 3(6): 1089-97. PMID: 11813982, DOI: 10.1089/152308601317203594, ISSN: 1523-0864.

Li X, Hill KE, Burk RF, May JM. Selenium spares ascorbate and alpha-tocopherol in cultured liver cell lines under oxidant stress. FEBS Lett. 2001 Nov 11/23/2001; 508(3): 489-92. PMID: 11728478, PII: S0014-5793(01)03129-5, ISSN: 0014-5793.

May JM, Qu Z, Morrow JD. Mechanisms of ascorbic acid recycling in human erythrocytes. Biochim. Biophys. Acta. 2001 Oct 10/3/2001; 1528(2-3): 159-66. PMID: 11687303, PII: S030441650100188X, ISSN: 0006-3002.

Lekse JM, Xia L, Stark J, Morrow JD, May JM. Plant catechols prevent lipid peroxidation in human plasma and erythrocytes. Mol. Cell. Biochem. 2001 Oct; 226(1-2): 89-95. PMID: 11768243, ISSN: 0300-8177.

May JM, Qu Z, Li X. Requirement for GSH in recycling of ascorbic acid in endothelial cells. Biochem. Pharmacol. 2001 Oct 10/1/2001; 62(7): 873-81. PMID: 11543722, PII: S0006295201007365, ISSN: 0006-2952.

May JM, Qu Z, Cobb CE. Recycling of the ascorbate free radical by human erythrocyte membranes. Free Radic. Biol. Med. 2001 Jul 7/1/2001; 31(1): 117-24. PMID: 11425497, PII: S0891584901005664, ISSN: 0891-5849.

Perriott LM, Kono T, Whitesell RR, Knobel SM, Piston DW, Granner DK, Powers AC, May JM. Glucose uptake and metabolism by cultured human skeletal muscle cells: rate-limiting steps. Am. J. Physiol. Endocrinol. Metab. 2001 Jul; 281(1): E72-80. PMID: 11404224, ISSN: 0193-1849.

Hill KE, Motley AK, Li X, May JM, Burk RF. Combined selenium and vitamin E deficiency causes fatal myopathy in guinea pigs. J. Nutr. 2001 Jun; 131(6): 1798-802. PMID: 11385070, ISSN: 0022-3166.

Li X, Cobb CE, Hill KE, Burk RF, May JM. Mitochondrial uptake and recycling of ascorbic acid. Arch. Biochem. Biophys. 2001 Mar 3/1/2001; 387(1): 143-53. PMID: 11368176, PII: S0003-9861(00)92245-8, DOI: 10.1006/abbi.2000.2245, ISSN: 0003-9861.

Li, X., Cobb, C.E, Hill, K.E., Burk, R.F., and May, J.M. Mitochondrial uptake and recycling of ascorbic acid. Arch. Biochem. Biophys. 2001; 387: 143-53.

Perriott, L., Kono, T., Whitesell, R.R., Knobel, S., Piston, D.W., Granner, D.K., Powers, A.C., and May, J.M. Glucose uptake and metabolism by cultured human skeletal muscle cells: rate-limiting steps. Am. J. Physiol. 2001; 281: E72-E80.

Hill, K.E., Motley, A.K., Li, X., May, J.M., and Burk, R.F. Combined selenium and vitamin E deficiency causes fatal myopathy in guinea pigs. J. Nutr. 2001; 131: 1798-802.

May, J.M., Qu, Z.-C., and Li, X. Requirement for GSH in recycling of ascorbic acid in endothelial cells. Biochem. Pharmacol. 2001; 63: 873-81.

May, J.M., Qu., Z.-C., and Cobb, C.E. Recycling of the ascorbate free radical by human erythrocyte membranes. Free Radic. Biol. Med. 2001; 31: 117-24.

May, J.M., Qu., Z.-C., and Morrow, J. Mechanisms of ascorbic acid recycling in human erythrocytes. Biochim.Biophys. Acta. 2001; 1528: 159-66.

May JM, Qu ZC, Xia L, Cobb CE. Nitrite uptake and metabolism and oxidant stress in human erythrocytes. Am. J. Physiol., Cell Physiol. 2000 Dec; 279(6): C1946-54. PMID: 11078710, ISSN: 0363-6143.

May JM, Qu Z, Morrow JD, Cobb CE. Ascorbate-dependent protection of human erythrocytes against oxidant stress generated by extracellular diazobenzene sulfonate. Biochem. Pharmacol. 2000 Jul 7/1/2000; 60(1): 47-53. PMID: 10807944, PII: S0006295200003129, ISSN: 0006-2952.

May JM. How does ascorbic acid prevent endothelial dysfunction?. Free Radic. Biol. Med. 2000 May 5/1/2000; 28(9): 1421-9. PMID: 10924860, PII: S0891-5849(00)00269-0, ISSN: 0891-5849.

May JM, Qu Zc, Cobb CE. Extracellular reduction of the ascorbate free radical by human erythrocytes. Biochem. Biophys. Res. Commun. 2000 Jan 1/7/2000; 267(1): 118-23. PMID: 10623584, PII: S0006291X9991906X, DOI: 10.1006/bbrc.1999.1906, ISSN: 0006-291X.

May JM, Qu ZC. Troglitazone protects human erythrocytes from oxidant damage. Antioxid. Redox Signal. 2000; 2(2): 243-50. PMID: 11229529, ISSN: 1523-0864.

May, J.M., Qu, Z.-C., and Cobb, C. Extracellular reduction of the ascorbate free radical by human erythrocytes. Biochem. Biophys. Res. Commun. 2000; 267: 118-23.

May, J.M., Qu, Z.-C., Morrow, J.D., and Cobb, C.E. Ascorbate-dependent protection of human erythrocytes against oxidant stress generated by diazobenzene sulfonate. Biochem. Pharmacol. 2000; 60: 47-53.

May, J.M. How does ascorbic acid prevent endothelial dysfunction?. Free Radic. Biol. Med. 2000; 28: 1421-9.

May, J.M., Qu, Z.-C., Li, X., and Cobb, C.E. Nitrite uptake and metabolism and oxidant stress in human erythrocytes. Amer. J. Physiol. 2000; 279: C1946-C1954.

Mitsuyama H, May JM. Uptake and antioxidant effects of ergothioneine in human erythrocytes. Clin. Sci. 1999 Oct; 97(4): 407-11. PMID: 10491340, ISSN: 0143-5221.

May JM, Qu ZC. Ascorbate-dependent electron transfer across the human erythrocyte membrane. Biochim. Biophys. Acta. 1999 Sep 9/21/1999; 1421(1): 19-31. PMID: 10561468, PII: S0005-2736(99)00107-8, ISSN: 0006-3002.

Ardehali H, Printz RL, Whitesell RR, May JM, Granner DK. Functional interaction between the N- and C-terminal halves of human hexokinase II. J. Biol. Chem. 1999 Jun 6/4/1999; 274(23): 15986-9. PMID: 10347146, ISSN: 0021-9258.

May JM, Mendiratta S, Qu ZC, Loggins E. Vitamin C recycling and function in human monocytic U-937 cells. Free Radic. Biol. Med. 1999 Jun; 26(11-12): 1513-23. PMID: 10401617, PII: S0891-5849(99)00017-9, ISSN: 0891-5849.

May JM. Is ascorbic acid an antioxidant for the plasma membrane?. FASEB J. 1999 Jun; 13(9): 995-1006. PMID: 10336882, ISSN: 0892-6638.

May JM, Qu ZC, Mendiratta S. Role of ascorbic acid in transferrin-independent reduction and uptake of iron by U-937 cells. Biochem. Pharmacol. 1999 Jun 6/1/1999; 57(11): 1275-82. PMID: 10230771, PII: S0006-2952(99)00040-4, ISSN: 0006-2952.

Vincent TE, Mendiratta S, May JM. Inhibition of aldose reductase in human erythrocytes by vitamin C. Diabetes Res. Clin. Pract. 1999 Jan; 43(1): 1-8. PMID: 10199583, PII: S0168-8227(98)00119-3, ISSN: 0168-8227.

Ross D, Mendiratta S, Qu ZC, Cobb CE, May JM. Ascorbate 6-palmitate protects human erythrocytes from oxidative damage. Free Radic. Biol. Med. 1999 Jan; 26(1-2): 81-9. PMID: 9890643, PII: S0891-5849(98)00198-1, ISSN: 0891-5849.

Ross, D., Qu, Z.-C., Cobb, C. E., and May, J.M. Protection of human erythrocytes from oxidation by ascorbate 6-palmitate, a membrane-bound ascorbic acid derivative. Free Radic. Biol. Med. 1999; 26: 81-9.

May, J.M., Mendiratta, S., Qu, Z.-C. Role of ascorbic acid in transferrin-independent reduction and uptake of iron by U-937 cells. Biochem.Pharmacol. 1999; 57: 1275-82.

May, J.M., Mendiratta, S., Qu, Z.-C., and Loggins, E. Vitamin C recycling and function in human monocytic U-937 cells. Free Radic. Biol. Med. 1999; 26: 1513-23.

Mitsuyama, H., and May, J.M. Uptake and antioxidant effects of ergothioneine in human erythrocytes. Clin. Sci. 1999; 97: 407-11.

May, J.M.. Ascorbate-dependent electron transfer across the human erythrocyte membrane. Biochim. Biophys. Acta. 1999; 1421: 19-31.

May JM, Cobb CE, Mendiratta S, Hill KE, Burk RF. Reduction of the ascorbyl free radical to ascorbate by thioredoxin reductase. J. Biol. Chem. 1998 Sep 9/4/1998; 273(36): 23039-45. PMID: 9722529, ISSN: 0021-9258.

Mendiratta S, Qu ZC, May JM. Enzyme-dependent ascorbate recycling in human erythrocytes: role of thioredoxin reductase. Free Radic. Biol. Med. 1998 Jul 7/15/1998; 25(2): 221-8. PMID: 9667500, PII: S0891-5849(98)00060-4, ISSN: 0891-5849.

Mendiratta S, Qu Z, May JM. Erythrocyte defenses against hydrogen peroxide: the role of ascorbic acid. Biochim. Biophys. Acta. 1998 May 5/8/1998; 1380(3): 389-95. PMID: 9555101, ISSN: 0006-3002.

Davis JL, Mendiratta S, May JM. Similarities in the metabolism of alloxan and dehydroascorbate in human erythrocytes. Biochem. Pharmacol. 1998 Apr 4/15/1998; 55(8): 1301-7. PMID: 9719486, PII: S0006295297006370, ISSN: 0006-2952.

Mendiratta S, Qu ZC, May JM. Erythrocyte ascorbate recycling: antioxidant effects in blood. Free Radic. Biol. Med. 1998 Mar 3/15/1998; 24(5): 789-97. PMID: 9586809, PII: S0891-5849(97)00351-1, ISSN: 0891-5849.

May JM, Qu ZC, Mendiratta S. Protection and recycling of alpha-tocopherol in human erythrocytes by intracellular ascorbic acid. Arch. Biochem. Biophys. 1998 Jan 1/15/1998; 349(2): 281-9. PMID: 9448716, PII: S0003-9861(97)90473-2, DOI: 10.1006/abbi.1997.0473, ISSN: 0003-9861.

May JM. Ascorbate function and metabolism in the human erythrocyte. Front. Biosci. 1998; 3: d1-10. PMID: 9405334, ISSN: 1093-9946.

May, J.M., Qu, Z.-C.., and A. Mendiratta. Protection and recycling of a-tocopherol in human erythrocytes by intracellular ascorbic acid. Arch. Biochem. Biophys. 1998; 349: 281-9.

May, J.M., Cobb, C.E., Mendiratta, S., Hill, K.E., and R.F. Burk. Reduction of the ascorbyl free radical to ascorbate by thioredoxin reductase. J. Biol. Chem. 1998; 273: 23039-45.

Mendiratta, S., Qu, Z.-C., and May, J.M. Erythrocyte ascorbate recycling: Antioxidant effects in blood. Free Radic. Bio. Med. 1998; 24: 789-97.

Davis, J. L., Jr., Mendiratta, S., and May, J.M.. Alloxan metabolism mimics that of dehydroascorbate in human erythrocytes. Biochem. Pharmacol. 1998; 55: 1301-7.

Mendiratta, S., Qu, Z.-C, and May, J.M. Erythrocyte defenses against hydrogen peroxide: The role of ascorbic acid. Biochim. Biophys. Acta. 1998; 1380: 389-95.

Mendiratta, S., Qu, Z.C., and May, J.M. Enzyme-dependent ascorbate recycling in human erythrocytes: role of thioredoxin reductase. Free Radic. Biol. Med. 1998; 25: 221-8.

May, J. M. Ascorbate function and metabolism in the human erythrocyte. Front. Biosci. 1998; 2: d1-d10.

May JM, Mendiratta S, Hill KE, Burk RF. Reduction of dehydroascorbate to ascorbate by the selenoenzyme thioredoxin reductase. J. Biol. Chem. 1997 Sep 9/5/1997; 272(36): 22607-10. PMID: 9278416, ISSN: 0021-9258.

Waters RE, White LL, May JM. Liposomes containing alpha-tocopherol and ascorbate are protected from an external oxidant stress. Free Radic. Res. 1997 Apr; 26(4): 373-9. PMID: 9167942, ISSN: 1071-5762.

May, J.M., Mendiratta, S., Hill, K.E., and R.F. Burk. Reduction of dehydroascorbate to ascorbate by the selenoenzyme thioredoxin reductase. J. Biol. Chem. 1997; 272: 22607-10.

Waters, R.E. II, White, L.L., and May, J.M. Liposomes containing alpha-tocopherol and ascorbate are protected from an external oxidant stress. Free Radical Res. 1997; 26: 373-9.

May JM, Qu ZC, Morrow JD. Interaction of ascorbate and alpha-tocopherol in resealed human erythrocyte ghosts. Transmembrane electron transfer and protection from lipid peroxidation. J. Biol. Chem. 1996 May 5/3/1996; 271(18): 10577-82. PMID: 8631858, ISSN: 0021-9258.

Ardehali H, Yano Y, Printz RL, Koch S, Whitesell RR, May JM, Granner DK. Functional organization of mammalian hexokinase II. Retention of catalytic and regulatory functions in both the NH2- and COOH-terminal halves. J. Biol. Chem. 1996 Jan 1/26/1996; 271(4): 1849-52. PMID: 8567628, ISSN: 0021-9258.

May JM, Qu ZC, Whitesell RR, Cobb CE. Ascorbate recycling in human erythrocytes: role of GSH in reducing dehydroascorbate. Free Radic. Biol. Med. 1996; 20(4): 543-51. PMID: 8904295, PII: 0891584995021302, ISSN: 0891-5849.

May JM, Qu ZC, Cobb CE. Accessibility and reactivity of ascorbate 6-palmitate bound to erythrocyte membranes. Free Radic. Biol. Med. 1996; 21(4): 471-80. PMID: 8886797, PII: 0891584996001232, ISSN: 0891-5849.

Ardehali, H., Yano, Y., Printz, R.L., Koch, S., Whitesell, R.R., May, J.M., and D.K. Granner. Functional organization of mammalian hexokinase II. Retention of catalytic and regulatory functions in both the NH2- and COOH-terminal halves. J. Biol.Chem. 1996; 271: 1849-52.

May, J.M., Zhi-chao, Q., Whitesell, R.R., and Cobb, C.E. Ascorbate recycling in human erythrocytes: role of GSH in reducing dehydroascorbate. Free Rad. Biol. Med. 1996; 20: 543-51.

May, J.M., Qu, Z.C., and Morrow, J.D. . Interaction of ascorbate and alpha-tocopherol in resealed erythrocyte ghosts - Transmembrane electron transfer and protection from lipid peroxidation. J.Biol.Chem. 1996; 271: 10577-82.

May, J.M., Qu, Z.-C., Whitesell, R.R., and Cobb, C.E. Accessibility and reactivity of ascorbate 6_palmitate bound to human erythrocytes. Free Rad. Biol. Med. 1996; 21: 471-80.

May JM, Qu ZC, Whitesell RR. Ascorbic acid recycling enhances the antioxidant reserve of human erythrocytes. Biochemistry. 1995 Oct 10/3/1995; 34(39): 12721-8. PMID: 7548025, ISSN: 0006-2960.

May JM, Qu ZC, Whitesell RR. Ascorbate is the major electron donor for a transmembrane oxidoreductase of human erythrocytes. Biochim. Biophys. Acta. 1995 Sep 9/13/1995; 1238(2): 127-36. PMID: 7548127, ISSN: 0006-3002.

Whitesell RR, Ward M, McCall AL, Granner DK, May JM. Coupled glucose transport and metabolism in cultured neuronal cells: determination of the rate-limiting step. J. Cereb. Blood Flow Metab. 1995 Sep; 15(5): 814-26. PMID: 7673374, DOI: 10.1038/jcbfm.1995.103, ISSN: 0271-678X.

Due AD, Qu ZC, Thomas JM, Buchs A, Powers AC, May JM. Role of the C-terminal tail of the GLUT1 glucose transporter in its expression and function in Xenopus laevis oocytes. Biochemistry. 1995 Apr 4/25/1995; 34(16): 5462-71. PMID: 7727404, ISSN: 0006-2960.

Due AD, Cook JA, Fletcher SJ, Qu ZC, Powers AC, May JM. A "cysteineless" GLUT1 glucose transporter has normal function when expressed in Xenopus oocytes. Biochem. Biophys. Res. Commun. 1995 Mar 3/17/1995; 208(2): 590-6. PMID: 7695611, PII: S0006-291X(85)71379-4, DOI: 10.1006/bbrc.1995.1379, ISSN: 0006-291X.

Due, A.D., Zhi-chao, Q., Powers, A.C. and May, J.M. The role of the C-terminal tail of the GLUT1 glucose transporter in its expression and function in Xenopus laevis oocytes. Biochemistry. 1995; 34: 5462-71.

May, J.M., Zhi-chao, Q. and Whitesell, R.R. Ascorbic acid recycling enhances the antioxidant reserve of human erythrocytes. Biochemistry. 1995; 34: 12721-8.

May, J.M., Zhi-chao, Q. and Whitesell, R.R. Ascorbate is the major electron donor for a transmembrane oxidoreductase of human erythrocytes. Biochim. Biophys. Acta. 1995; 1238: 127-36.

Morita H, Yano Y, Niswender KD, May JM, Whitesell RR, Wu L, Printz RL, Granner DK, Magnuson MA, Powers AC. Coexpression of glucose transporters and glucokinase in Xenopus oocytes indicates that both glucose transport and phosphorylation determine glucose utilization. J. Clin. Invest. 1994 Oct; 94(4): 1373-82. PMID: 7929812, PMCID: PMC295259, DOI: 10.1172/JCI117472, ISSN: 0021-9738.

Whitesell RR, Aboumrad MK, Powers AC, Regen DM, Le C, Beechem JM, May JM, Abumrad NA. Coupling of glucose transport and phosphorylation in Xenopus oocytes and cultured cells: determination of the rate-limiting step. J. Cell. Physiol. 1993 Dec; 157(3): 509-18. PMID: 8253862, DOI: 10.1002/jcp.1041570310, ISSN: 0021-9541.

Yano Y, May JM. Ligand-induced conformational changes modify proteolytic cleavage of the adipocyte insulin-sensitive glucose transporter. Biochem. J. 1993 Oct 10/1/1993; 295 ( Pt 1): 183-8. PMID: 8216214, PMCID: PMC1134836, ISSN: 0264-6021.

May JM, Qu ZC, Beechem JM. Tryptic digestion of the human erythrocyte glucose transporter: effects on ligand binding and tryptophan fluorescence. Biochemistry. 1993 Sep 9/21/1993; 32(37): 9524-31. PMID: 8373759, ISSN: 0006-2960.

Feman SS, Mericle RA, Reed GW, May JM, Workman RJ. Serum angiotensin converting enzyme in diabetic patients. Am. J. Med. Sci. 1993 May; 305(5): 280-4. PMID: 8387241, ISSN: 0002-9629.

May JM, Beechem JM. Monitoring conformational change in the human erythrocyte glucose carrier: use of a fluorescent probe attached to an exofacial carrier sulfhydryl. Biochemistry. 1993 Mar 3/23/1993; 32(11): 2907-15. PMID: 8457556, ISSN: 0006-2960.

May, J.M. and Beechem, J.M.. Monitoring conformational change in the human erythrocyte glucose carrier: use of a fluorescent probe attached to an exofacial carrier sulfhydryl. Biochemistry. 1993; 32: 2907-15.

May, J.M., Zhi-Chao, Q., and Beechem, J.M.. Tryptic digestion of the human erythrocyte glucose transporter: effects on ligand binding and tryptophan fluorescence. Biochemistry. 1993; 32: 9524-31.

May JM. The one-site model of human erythrocyte glucose transport: testing its predictions using network thermodynamic computer simulations. Biochim. Biophys. Acta. 1991 Apr 4/26/1991; 1064(1): 1-6. PMID: 2025630, PII: 0005-2736(91)90404-V, ISSN: 0006-3002.

May JM, Buchs A, Carter-Su C. Localization of a reactive exofacial sulfhydryl on the glucose carrier of human erythrocytes. Biochemistry. 1990 Nov 11/13/1990; 29(45): 10393-8. PMID: 2261480, ISSN: 0006-2960.

May JM. Thiol-fatty acylation of the glucose transport protein of human erythrocytes. FEBS Lett. 1990 Nov 11/12/1990; 274(1-2): 119-21. PMID: 2253764, PII: 0014-5793(90)81344-N, ISSN: 0014-5793.

May JM. Differential labeling of the erythrocyte hexose carrier by N-ethylmaleimide: correlation of transport inhibition with reactive carrier sulfhydryl groups. Biochim. Biophys. Acta. 1989 Nov 11/27/1989; 986(2): 207-16. PMID: 2590670, ISSN: 0006-3002.

May JM. Interaction of a permeant maleimide derivative of cysteine with the erythrocyte glucose carrier. Differential labelling of an exofacial carrier thiol group and its role in the transport mechanism. Biochem. J. 1989 Nov 11/1/1989; 263(3): 875-81. PMID: 2489029, PMCID: PMC1133512, ISSN: 0264-6021.

May JM. Inhibition of hexose transport in the human erythrocyte by 5, 5'-dithiobis(2-nitrobenzoic acid): role of an exofacial carrier sulfhydryl group. J. Membr. Biol. 1989 Jun; 108(3): 227-33. PMID: 2778797, ISSN: 0022-2631.

May JM. Selective labeling of the erythrocyte hexose carrier with a maleimide derivative of glucosamine: relationship of an exofacial sulfhydryl to carrier conformation and structure. Biochemistry. 1989 Feb 2/21/1989; 28(4): 1718-25. PMID: 2719930, ISSN: 0006-2960.

May JM. Effects of ATP depletion on the mechanism of hexose transport in intact human erythrocytes. FEBS Lett. 1988 Dec 12/5/1988; 241(1-2): 188-90. PMID: 3143605, PII: 0014-5793(88)81058-5, ISSN: 0014-5793.

May JM. Reaction of an exofacial sulfhydryl group on the erythrocyte hexose carrier with an impermeant maleimide. Relevance to the mechanism of hexose transport. J. Biol. Chem. 1988 Sep 9/25/1988; 263(27): 13635-40. PMID: 3417676, ISSN: 0021-9258.

May JM. Inhibition of hexose transport and labelling of the hexose carrier in human erythrocytes by an impermeant maleimide derivative of maltose. Biochem. J. 1988 Sep 9/1/1988; 254(2): 329-36. PMID: 3178762, PMCID: PMC1135081, ISSN: 0264-6021.

May JM, Danzo BJ. Photolabeling of the human erythrocyte glucose carrier with androgenic steroids. Biochim. Biophys. Acta. 1988 Aug 8/18/1988; 943(2): 199-210. PMID: 3401477, PII: 0005-2736(88)90552-4, ISSN: 0006-3002.

May JM. Inhibition of hexose transport by adenosine derivatives in human erythrocytes. J. Cell. Physiol. 1988 May; 135(2): 332-8. PMID: 3372599, DOI: 10.1002/jcp.1041350222, ISSN: 0021-9541.