scholarly journals INTERRELATIONS OF VITAMIN B12 AND FOLIC ACID METABOLISM: FOLIC ACID CLEARANCE STUDIES*

1962 ◽  
Vol 41 (6) ◽  
pp. 1263-1276 ◽  
Author(s):  
Victor Herbert ◽  
Ralph Zalusky
Keyword(s):  
Folic Acid ◽  
Vitamin B12 ◽  
Acid Metabolism ◽  
Acid Clearance ◽  
Folic Acid Metabolism ◽  
Clearance Studies

scholarly journals Folic acid metabolism in vitamin B12-deficient sheep. Effects of injected methionine on liver constituents associated with folate metabolism

1974 ◽  
Vol 142 (1) ◽  
pp. 105-117 ◽  
Author(s):  
Richard M. Smith ◽  
William S. Osborne-White ◽  
Jeffrey M. Gawthorne
Keyword(s):  
Folic Acid ◽  
Ion Exchange ◽  
Vitamin B12 ◽  
Lactobacillus Casei ◽  
Acid Metabolism ◽  
Major Effect ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Folate Metabolism ◽  
Folic Acid Metabolism

1. The effects of injected l-methionine (2g every second day for 28 days) on liver folates and other constituents of liver associated with folate metabolism were studied in vitamin B12-deficient ewes and their pair-fed controls receiving vitamin B12. The dose rate of methionine used was sufficient to restore almost to normal the elevated excretion in the urine of formiminoglutamate in the deficient animals. 2. Liver folates active for Lactobacillus casei, Streptococcus faecalis R and Pediococcus cerevisiae were severely depressed in deficient livers and were partly restored by methionine. Analysis of the folates after ion-exchange chromatography showed that the major effect of methionine was to increase the concentrations of tetrahydrofolates and formyltetrahydrofolates. Methyltetrahydrofolates were also increased, but there was no effect of methionine on the small amounts of incompletely reduced folates present in deficient livers. The folates present were predominantly penta-, hexa- and hepta-glutamates whether or not animals received vitamin B12 or methionine. 3. Concentrations of ATP, NAD+, NADH and NADPH were lower in freeze-clamped liver from vitamin B12-deficient sheep than in liver from pair-fed, vitamin B12-treated sheep. These changes were not affected by methionine which was also without effect on the elevated K+/Na+ ratios found in deficient livers. 4. The livers of vitamin B12-deficient animals contained lower concentrations of choline and higher concentrations of lipid than their pair-fed controls. These effects were reversed by methionine.

scholarly journals Subnormal Serum Folate and Macrocytosis Associated with Anticonvulsant Drug Therapy

Blood ◽  
1964 ◽  
Vol 23 (1) ◽  
pp. 68-86 ◽  
Author(s):  
FREDERICK A. KLIPSTEIN
Keyword(s):  
Folic Acid ◽  
Drug Therapy ◽  
Acid Metabolism ◽  
Culture Media ◽  
Serum Vitamin ◽  
Anticonvulsant Drug ◽  
Serum Folate ◽  
Normal Range ◽  
Folic Acid Metabolism ◽  
Clearance Studies

Abstract Hematologic studies and microbiological assay of serum folate levels with L. casei and serum vitamin B12 concentrations with L. leichmannii were performed on 60 subjects receiving anticonvulsant drug therapy and five epileptics receiving no treatment. Subnormal serum folate levels of less than 5.0 mµg./ml. were observed in 58 per cent of 53 subjects receiving Dilantin and one of seven patients on other anticonvulsant agents. The incidence of subnormal serum folate values was greater in those subjects who had been taking Dilantin for periods of time greater than 5 years, but did not appear to bear any correlation to the dosage of the drug. Slight or moderate macrocytosis was observed in 71 per cent of subjects receiving Dilantin who had subnormal serum folate levels and in 18 per cent of subjects with normal levels. Serum B12 concentrations were within the normal range. The growth of L. casei was not inhibited by anticonvulsant drugs when added to culture media containing folic acid or serum from patients on Dilantin with normal or low folate concentrations. Folic acid clearance studies were abnormally rapid in three of nine patients studied who were receiving Dilantin. Possible sites of metabolic inhibition resulting in disturbances in folic acid metabolism during therapy with anticonvulsant medications are discussed.

Folic Acid Metabolism

1959 ◽  
Vol 7 (3) ◽  
pp. 302-310
Author(s):  
A. V. TRUFANOV
Keyword(s):  
Folic Acid ◽  
Acid Metabolism ◽  
Folic Acid Metabolism
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