Haptocorrin in humans
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Anne L. Morkbak
Abstract
Background: Evolutionary haptocorrin is the youngest of the cobalamin-binding proteins. It evolved by duplication of the intrinsic factor gene and has been identified in most mammals examined. Its ability to bind both cobalamin and analogues is well established, but apart from that, our knowledge concerning its function and its distribution in adult and foetal life is limited. In this study, we present data on the tissue expression of haptocorrin and on the relation between analogues on haptocorrin and vitamin B12 status in humans.
Methods: Polyclonal antibodies towards haptocorrin were used to study the localisation in foetal and adult tissues by immunohistochemistry. Positive immunoreactions were primarily observed in exocrine glands, the gastrointestinal tract and the respiratory system. ELISA was used for measurement of holo- and total haptocorrin in blood samples from individuals diagnosed with vitamin B12 deficiency, based on measurement of methylmalonic acid (μmol/L) as evident (>0.75, n=61), suspected (0.29–0.75, n=155) or not present (<0.29, n=170). Cobalamins and holotranscobalamin were measured in the same individuals.
Results: Holohaptocorrin was considerably higher than holohaptocorrin-cobalamins (cobalamins minus holotranscobalamin). The median (25th–75th percentile, pmol/L) for holohaptocorrin analogues (holohaptocorrin minus holohaptocorrin-cobalamins) was higher in deficient [200 (130–240)] compared to the non-deficient [140 (80–200)] individuals (analysis of variance and Tukey's multiple comparison test, p<0.01).
Conclusions: Our results indicate that haptocorrin is widely distributed also in foetal tissues and suggest analogues to accumulate on haptocorrin in vitamin B12-deficient individuals, a result that warrants further studies employing methods directly measuring cobalamins and analogues attached to haptocorrin.
Clin Chem Lab Med 2007;45:1751–9.
©2007 by Walter de Gruyter Berlin New York
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- Association between homocysteine, vitamin B6 concentrations and inflammation
- Quantitative profiling of folate and one-carbon metabolism in large-scale epidemiological studies by mass spectrometry
- Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
- Haptocorrin in humans
- Small ubiquitin-like modifier-1 (SUMO-1) modification of thymidylate synthase and dihydrofolate reductase
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- Synergism between AT1 receptor and hyperhomocysteinemia during vascular remodeling
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- The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial
- Acknowledgement
- Contents, Volume 45, 2007
- Author Index
- Subject Index
Articles in the same Issue
- Homocysteine research: alive and kicking!
- Homocysteine-lowering trials for prevention of vascular disease: protocol for a collaborative meta-analysis
- Perspective on the efficacy analysis of the Vitamin Intervention for Stroke Prevention trial
- Homocysteine-lowering vitamin B treatment decreases cardiovascular events in hemodialysis patients
- The role of hyperhomocysteinemia and B-vitamin deficiency in neurological and psychiatric diseases
- Management of L-Dopa related hyperhomocysteinemia: catechol-O-methyltransferase (COMT) inhibitors or B vitamins? Results from a review
- Biomarkers of folate and vitamin B12 status in cerebrospinal fluid
- The role of hyperhomocysteinemia as well as folate, vitamin B6 and B12 deficiencies in osteoporosis – a systematic review
- Homocysteine, brain natriuretic peptide and chronic heart failure: a critical review
- Homocysteine, left ventricular dysfunction and coronary artery disease: is there a link?
- Hyperhomocysteinemia and high-density lipoprotein metabolism in cardiovascular disease
- Hyperhomocysteinemia, DNA methylation and vascular disease
- Measuring subclinical atherosclerosis: is homocysteine relevant?
- Plasma protein homocysteinylation in uremia
- Homocysteine and asymmetric dimethylarginine (ADMA): biochemically linked but differently related to vascular disease in chronic kidney disease
- Hyperhomocysteinemia – association with renal transsulfuration and redox signaling in rats
- Metabolic regulatory properties of S-adenosylmethionine and S-adenosylhomocysteine
- Defects in homocysteine metabolism: diversity among hyperhomocyst(e)inemias
- The molecular basis of homocysteine thiolactone-mediated vascular disease
- Importance of folate-homocysteine homeostasis during early embryonic development
- Association between homocysteine, vitamin B6 concentrations and inflammation
- Quantitative profiling of folate and one-carbon metabolism in large-scale epidemiological studies by mass spectrometry
- Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid
- Haptocorrin in humans
- Small ubiquitin-like modifier-1 (SUMO-1) modification of thymidylate synthase and dihydrofolate reductase
- Decreased p66Shc promoter methylation in patients with end-stage renal disease
- Synergism between AT1 receptor and hyperhomocysteinemia during vascular remodeling
- Differential expression of γ-aminobutyric acid receptor A (GABAA) and effects of homocysteine
- The effect of B-vitamins on biochemical bone turnover markers and bone mineral density in osteoporotic patients: a 1-year double blind placebo controlled trial
- Acknowledgement
- Contents, Volume 45, 2007
- Author Index
- Subject Index
