Tissue Distribution and Prediction of Total Body Folate of Rats

Abstract

To clarify relationships between dietary folic acid intake, blood levels and body stores of folate, rats were fed an amino acid-based diet supplemented with 0, 0.125, 0.5, 1, 2 or 4 mg folic acid/kg diet for 25 d. Folate concentrations of carcass, liver, gastrointestinal (GI) tract, kidney, spleen, testes, heart and lung from rats fed the folate-free diet were 0.06 +/- 0.01, 0.73 +/- 0.08, 0.05 +/- 0.01, 0.39 +/- 0.01, 0.05 +/- 0.01, 0.17 +/- 0.01, 0.02 +/- 0.01 and 0.02 +/- 0.01 micrograms/g, respectively. Serum and erythrocyte concentrations and total body stores were 0.88 +/- 0.16 ng/mL, 0.30 +/- 0.01 micrograms/mL and 13.9 +/- 0.7 micrograms, respectively. Body folate distribution was carcass, 55.6 +/- 1.4%; liver, 26.0 +/- 1.9%; erythrocytes, 7.7 +/- 0.4%; kidney, 4.8 +/- 0.2%; GI tract, 3.0 +/- 0.2%; and testes, 2.5 +/- 0.2%. Carcass content dropped to 38% whereas liver content increased to 44% in rats fed the highest dietary level. Tissue concentrations were correlated with one another and with dietary folate levels. Under these experimental conditions total body folate could be predicted from serum folate, but the general applicability of this relationship requires further study.

Pharmacokinetics and bioavailability of folic acid and plasma levels of bioactive folates after folic acid administration to pigs

“…Since the folate level decreases in plasma before its tissue depletion, and this decrease in plasma is paralleled by a reduction in red blood cell folate, the levels in plasma are important clinical indicators that reflect the folate status of the body of many mammalian species (1, 2,5,8). It has been reported that serum folate levels decrease during pregnancy in pigs (11).…”

Relative bioavailability of folate from the traditional food plant Moringa oleifera L. as evaluated in a rat model

“…Folate intake directly influences the plasma folate concentrations, whereas tissue folate levels saturate at high folate intakes (Clifford et al 1990). To elevate the tissue folate levels, dose of 5-formyl-THF are more beneficial than folic acid or 5-methyl-THF.…”

Maternal folic acid consumption during gestation and its long-term effects on offspring's liver: a systematic review

“…26 Nonetheless, mammalian cells are not able to uptake long chain length of polyglutamates (three and above). 27 The liver is able to absorb much of the folate that entered the portal circulation.…”