Removal of Cobalamin Analogue in Bile by Enterohepatic Circulation of Vitamin B12

S, Kanazawa; Herbert, Victor; Herzlich, Barry C.; Drivas, G; Manusselis, Cathy

doi:10.1016/s0140-6736(83)91996-7

Cited by 40 publications

(12 citation statements)

References 10 publications

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“…Therefore, it seemed that the corri noids excreted in bile corresponded mainly to Cbl analogues. Similar data have been recently obtained using another isotope dilu tion method [21]. However, a direct determi nation of Cbl analogues in bile and serum using high-pressure liquid chromatography would be necessary to confirm our data but this method is not available at the moment.…”

Section: Discussionsupporting

confidence: 86%

Biliary Excretion of Cobalamin and Cobalamin Analogues in Man

Guéant¹,

Monin²,

Boissel³

et al. 1984

Digestion

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Using dialysis, gel filtration, isoelectrofocusing and radioaffinity assay, we studied the unsaturated and saturated binders of bile and the biliary concentration of cobalamin (Cbl) and Cbl analogues compared to the corresponding serum concentrations in 7 choledochodomized patients. Bile contained a single saturated or unsaturated R binder with a molecular mass of about 120,000. Differences in the isoelectrofocusing pattern were observed between unsaturated and saturated R binders and could correspond to two secretion origins, mucosal secretion and hepatocyte clearance, respectively. The concentration of total corrinoids is about 4 times higher in bile than in serum, and this could be explained by a hepatic clearance of serum Cbl analogue-R binder complexes, as previously described in the rabbit. Moreover, the enterohepatic circulation of Cbl seems likely in healthy individuals since the saturated biliary R binder is degraded by pancreatic juice.

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Section: Discussionsupporting

confidence: 86%

Biliary Excretion of Cobalamin and Cobalamin Analogues in Man

Guéant¹,

Monin²,

Boissel³

et al. 1984

Digestion

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“…Moreover, the role of enterohepatic recirculation of B 12 conjugates requires further investigation because we postulate that this pathway may aid in prolonging the half-life of the B 12 -insulin conjugate. [21] The most remarkable finding of this study was the hypoglycemic response to the oral administration of the B 12 -insulin conjugate and its dependence on the B 12 uptake mechanism. However, while the clinical significance of this conjugate requires further investigation, it must be noted that the B 12 uptake capacity in humans is limited to approximately 1-2 mg per dosage and as such, the amount of peptide that can be introduced through the B 12 pathway is limited.…”

mentioning

confidence: 71%

Vitamin B₁₂ as a Carrier for the Oral Delivery of Insulin

Petrus¹,

Vortherms²,

Fairchild³

et al. 2007

ChemMedChem

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“…Some analogues are oxidative by-products of cobalamin metabolism [22], perhaps a consequence of the oxidative stress associated with AD [23]. Others are of gastrointestinal origin, either from dietary sources or from the enterohepatic circulation that exists to remove them [24].…”

Section: Discussionmentioning

confidence: 99%

Analogues, Ageing and Aberrant Assimilation of Vitamin B12 in Alzheimer’s Disease

McCaddon¹,

Hudson²,

Abrahamsson³

et al. 2001

Dement Geriatr Cogn Disord

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Vitamin B12 assimilation might be disrupted in patients with Alzheimer’s disease. We therefore measured B12 carrier protein saturation and inactive B12 ‘analogues’ in patients compared with healthy elderly individuals in a prospective case-controlled survey. Twenty-three patients, aged 60 or over, with features compatible with DSM-IV criteria for primary degenerative dementia of the Alzheimer type were recruited together with 18 cognitively intact age-matched control subjects. Total vitamin B12 (active corrinoids), holo- and apo-haptocorrin and transcobalamin were measured in serum. B12 analogues (inactive corrinoids) were estimated from the difference between R-binder-determined corrinoids and an intrinsic factor based B12 assay. Alzheimer patients had significantly lower active corrinoid than control subjects and the analogue/corrinoid ratio was significantly higher in the Alzheimer group. The inter-relationship between age, analogues and transcobalamin polarised patients into two distinct groups. Two disparate mechanisms might exist for the development of cerebral B12 deficiency in Alzheimer’s disease, although both imply a disruption of selective B12 assimilation and analogue elimination in such patients.

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Removal of Cobalamin Analogue in Bile by Enterohepatic Circulation of Vitamin B12

Cited by 40 publications

References 10 publications

Biliary Excretion of Cobalamin and Cobalamin Analogues in Man

Biliary Excretion of Cobalamin and Cobalamin Analogues in Man

Vitamin B₁₂ as a Carrier for the Oral Delivery of Insulin

Analogues, Ageing and Aberrant Assimilation of Vitamin B12 in Alzheimer’s Disease

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Removal of Cobalamin Analogue in Bile by Enterohepatic Circulation of Vitamin B12

Cited by 40 publications

References 10 publications

Biliary Excretion of Cobalamin and Cobalamin Analogues in Man

Biliary Excretion of Cobalamin and Cobalamin Analogues in Man

Vitamin B12 as a Carrier for the Oral Delivery of Insulin

Analogues, Ageing and Aberrant Assimilation of Vitamin B12 in Alzheimer’s Disease

Contact Info

Product

Resources

About

Vitamin B₁₂ as a Carrier for the Oral Delivery of Insulin