Estimation of the 5-methyltetrahydrofolate apparent volume of distribution in humans

The fractional absorption of a stable isotope-labeled folate dose can be estimated from the subsequent short-term temporal changes in the concentration of labeled L-5-methyltetrahydrofolate (L-5-methyl-THF) in plasma using mathematical modeling. However, the model is dependent on the use of an accurate value for the apparent volume of distribution of L-5-methyl-THF. Previous studies that estimated the apparent volume of distribution of L-5-methyl-THF used large (nonphysiological) doses of unlabeled folates that are not found to any great extent in the circulatory system. The current study estimates the apparent volume of distribution at steady state in 16 healthy humans aged 18-65 y after an i.v. dose (440 nmol) of a stable isotope-labeled version of the naturally circulating plasma folate, L-5-methyl-THF. Blood was collected from 2 min to 2 h postinjection and plasma assayed by specific and sensitive liquid chromatography-tandem MS. The apparent volume of distribution for L-5-methyl-THF was 32.0 ± 11.6 L (mean ± SD; 392 ± 110 mL/kg bodyweight). There was a positive association with volunteer body weight (r = 0.64; P = 0.010), which allowed a simple linear equation to be developed relating apparent volume of distribution to body weight. This has important implications for predicting apparent absorption of labeled folates in future bioavailability studies.

Medienart:

E-Artikel

Erscheinungsjahr:

2012

Erschienen:

2012

Enthalten in:

Zur Gesamtaufnahme - volume:142

Enthalten in:

The Journal of nutrition - 142(2012), 2 vom: 01. Feb., Seite 389-95

Sprache:

Englisch

Beteiligte Personen:

King, Maria J [VerfasserIn]
Brima, Eid I [VerfasserIn]
Dainty, Jack R [VerfasserIn]
Barrett, David A [VerfasserIn]
Wright, Anthony J [VerfasserIn]
Willis, Gavin [VerfasserIn]
Finglas, Paul M [VerfasserIn]

Links:

Volltext

Themen:

5-methyltetrahydrofolate
Carbon Isotopes
Clinical Trial
EC 1.5.1.20
Journal Article
Methylenetetrahydrofolate Reductase (NADPH2)
Research Support, Non-U.S. Gov't
TYK22LML8F
Tetrahydrofolates

Anmerkungen:

Date Completed 26.03.2012

Date Revised 16.02.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.3945/jn.111.143685

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM214355292