geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Absorption of pteroylglutamate and dietary folates in man


, : Absorption of pteroylglutamate and dietary folates in man. American Journal of Clinical Nutrition 25(11): 1135-1139

Folic acid, in amounts varying from 200 to 1000 mu g in 100 ml water, was given by mouth to 20 healthy, fasting medical students and serum activity was estimated with Lactobacillus casei, Streptococcus faecalis No.9 and, in a few cases, with pediococcus cerevisiae. In addition, groups of 5 fasting students took a meal of fresh vegetables and bread together with 20, 50 or 130 g fried beef liver. The liver was homogenised and an aliquot, assayed with L. casei, was found to contain folacin 15 mu g/g.A considerable rise in serum folacin active for S. faecalis was observed in all students who took 200 mu g folic acid. This rise reached a 2.2-fold peak within 60 min, after which activity rapidly declined. Less than 1% of the dose was excreted in the urine within 6 h. With doses of 500 and 1000 mu g, increases of serum activity up to 12 times the basic fasting level were found. Bioassays of serum with P. cerevisiae and with L. casei were also made before and after doses of 200, 500 and 1000 mu g folic acid, in order to find out whether it was transformed during absorption into other forms. No increase in serum folacin activity was found with P. cerevisiae but, depending on the dose of folic acid, a 1.4- to 2.8-fold increase in serum activity was obtained for L. casei.An average increase above the fasting level in serum folacin activity of 14 ng/ml was found with L. casei in a group of 5 student volunteers 30 min after they had eaten 130 g beef liver; the serum activity continued to rise to 19 ng/ml after 60 min and a peak of 29 ng/ml after 2 h, then it declined slowly. Similar, but smaller, increases in activity were found after consumption of 50 g and even of 20 g liver when serum was tested with L. casei; but when corresponding samples were assayed with S. faecalis or with P. cerevisiae, only negligible increases in activity were found.From the results which are discussed in detail, it was considered reasonable to assume that 5-methyltetrahydrofolate, the major folacin of the liver, is also the one absorbed from the gut; while the rapid and sustained rise found of activity for L. casei in the serum after ingestion of liver suggested a more efficient handling of the stored form than of the synthetic monoglutamate.

US$29.90

PMID: 4628665


Other references

Anonymous, 2012: Expert System For Identification and Management of Tobacco Diseases. Utilizing the best of the information on various diseases of tobacco and their symptoms, an expert system was developed for identification and management of these diseases. The expert system was developed using Visual Basic.Net as front-end applic...

Bach, T.; Morigen; Skarstad, K., 2008: The initiator protein DnaA contributes to keeping new origins inactivated by promoting the presence of hemimethylated DNA. The Escherichia coli replication origin oriC and other regions with high numbers of GATC sites remain hemimethylated after replication much longer than regions with average numbers of GATC sites. The prolonged period of hemimethylation has been at...

Du, J.; Li, M., 2017: Functions of Periostin in dental tissues and its role in periodontal tissues' regeneration. The goal of periodontal regenerative therapy is to predictably restore the tooth's supporting periodontal tissues and form a new connective tissue attachment of periodontal ligament (PDL) fibers and new alveolar bone. Periostin is a matricell...

Cribb, P., 1985: Paphiopedilum fairrieanum. Kew magazine 2(4)

Delles, C.; Husi, H., 2017: Systems Biology Approach in Hypertension Research. Systems biology is an approach to study all genes, gene transcripts, proteins, metabolites, and their interactions in specific cells, tissues, organs, or the whole organism. It is based on data derived from high-throughput analytical technologies...

Chalabi, M.; Duluc, C.; Caron, P.; Vezzosi, D.; Guillermet-Guibert, J.; Pyronnet, Séphane.; Bousquet, C., 2014: Somatostatin analogs: does pharmacology impact antitumor efficacy?. Somatostatin is an endogenous inhibitor of secretion and cell proliferation. These features render somatostatin a logical candidate for the management of neuroendocrine tumors that express somatostatin receptors. Synthetic somatostatin analogs (SS...

Walker, D.W.; Davies, A.N.; McMillen, I.C., 1990: Effect of hyperthermia on the plasma concentrations of prolactin and cortisol in the fetal lamb and pregnant ewe during late gestation. Exposing pregnant sheep to an ambient temperature of 43 .+-. 1.degree. C for 8 h was associated with a 1-1.5.degree. C increase of maternal and fetal core temperatures, and a 11-fold and 3-5 fold increase in maternal and fetal plasma prolactin con...

Nappi P., 1983: The influence of soil treatment and season on vesicular arbuscular mycorrhiza of apples malus domestica. Rootlets of apple trees and soil samples were compared for mycorrhizal development in soil given 3 different treatments: bark-mulch, grass mulch, mechanical and chemical weeding. Spore number and mycorrhizal incidence were surveyed at different ti...

Anonymous, 1955: Report on results of cultivation trials in 1954. Sowing dates for sugar-beet (trials conducted by Institutes at Jena, Halle/Lauchstadt, Leipzig and Rostock). Better yields were obtained from sowing in mid-April than from later sowings from end-of April to mid-May. The normal farm practice is the...

Praveen Kumar, P.; Preetam Raj, J.P.; Nimal Christhudas, I.V.S.; Sagaya Jansi, R.; Narbert Raj, M.; Agastian, P., 2014: α-Glucosidase inhibition and antioxidant properties of Streptomyces sp.: in vitro. Streptomyces strain isolated from the soil sediment was studied for its in vitro α-glucosidase and antioxidant properties. Morphological characterization and 16S rRNA partial gene sequencing were carried out to confirm that the strain Loyola AR1...