Folic acid deficiency anemia caused by therapy in chronic renal insufficiency

The turbidimetric determination of folic acid concentration in serum and erythrocytes was made by means of a spectrophotometer multiscan in 35 conservatively treated patients with chronic renal failure with a minimum creatine retention of 309 mumol/l and in 63 hemodialysed patients with terminal renal insufficiency. The result showed a statistically significant diminution of serum folic acid concentration in those patients treated in a conservative manner and a significant diminution of plasmatic and erythrocytic folate++ activity in patients under hemodialysis. There was a correlation between the folic acid concentration and the hemoglobin level in both groups of patients, whereas there was no correlation to the number of leukocytes and thrombocytes. A protein deficiency diet or loss of dialysis through the capillary membrane could be found to be the cause for the loss of folic acid. The possibility of folate++ substitutive therapy and its performance was discussed and recommended for selected indications.     

Folic acid deaminase activity during development in Dictyostelium discoideum.

Folic acid attracts vegetative amoebae of Dictyostelium discoideum. Secreted by bacteria, it may act as a food-seeking device. The inactivation of this attractant is catalyzed by a deaminase. As assay has been developed to measure the folic acid deaminase activity. In addition to cell-surface an intracellular deaminase, the amoebae of D. discoideum release the enzyme into the medium. The pH optimum of the extracellular enzyme was 6.0, and higher for the cell-associated deaminases. The extracellular enzyme was secreted maximally by vegetative amoebae, and its activity diminished during cell differentiation. The cell-surface bound enzyme was less active than the extracellular enzyme, and its activity decreased twofold during a 6-h starvation period. The enzyme activity of homogenates and 48,000 x g pellets diminished during this period 35 to 40%. The supernatant of a homogenate had a higher deaminase activity than the homogenate itself or its pellet; this suggests the presence of an inhibitor in the particulate fraction. The underlying mechanism for inactivation of folic acid has similar characteristics as that for inactivation of cyclic adenosine monophosphate.     

Folic acid deficiency and methyl group metabolism in rat brain: effects of L-dopa

Rats deficient in folic acid were found to have decreased concentrations of S-adenosylmethione in brain, kidney, and liver. They also showed decreased concentrations of methionine in serum, but not in brain. Administration of l-dopa (a methyl acceptor) in doses comparable to those used in the treatment of Parkinson's disease caused significant reductions in the concentrations of brain methionine in rats deficient in folic acid (45%, 45 min after administration), but failed to alter methionine concentrations in control animals. The changes in brain methionine brought about by l-dopa were not paralleled by similar changes in serum methionine, which decreased by only 20%. These observations suggest that de novo methyl group synthesis contributes significantly to the maintenance of brain methionine concentrations. The possibility is raised that the daily requirements for folic acid and for vitamin B₁₂ may be increased in human patients treated chronically with large doses of l-dopa.     

Folic acid biosensors: A review

Folic acid (FA) also known as (N-[p-{[(2-amino-4-hydroxy-6-pteridinyl) methyl] amino} benzoyl]-l-glutamic acid), is a water soluble vitamin found in plants and animals. The deficiency of FA leads to an increased risk of various diseases like neural tube defects in newborn, cardiovascular disease, cancer, Alzheimer’s disease and megaloblastic anemia. The normal levels of FA in human blood serum should fall in the range between 2 and 15 ng/mL. Present review article discusses the classification, principles, advantages and disadvantages of FA biosensing methods. FA biosensors operate within 3–300 s, in pH range, 1.8–7.8, concentration range 8.71 × 10⁻⁹ μM for FA. The FA biosensors displayed detection limits (LOD) between 1.6 × 10⁻¹¹ to 0.091 μM and with working potential −0.88 to 4.5 V. These biosensors measured FA level in various biological and pharmaceuticals samples.     

Folic acid compounds in romaine lettuce.

The composition of folate coenzymes in romaine lettuce was studied. Lettuce extract was purified on QAE-Sephadex A-25 and folate compounds were separated into a monoglutamate fraction and a polyglutamate fraction by chromatography on Sephadex G-15. Both the mono- and poly-glutamate fractions were resolved on DEAE-cellulose. Positive identification of DEAE peaks was made by further cochromatography with high specific activity radioactive marker folate compounds and with differential microbiological assay. The distribution of folate compounds in lettuce is as follows: 32% 5-CH3-H4PteGlu; 1% 5-CHO-H4PteGlu; 3% 5-CHO-H4PteGlu4; 9% 5-CH3-H4PteGlu4; 13% 5-CHO-H4PteGlu5; and 31% 5-CH3-H4PteGlu5.