AJP - Regulatory, Integrative and Comparative Physiology, Vol 270, Issue 1 99-104, Copyright © 1996 by American Physiological Society
Alteration of plasma folates in gestating sows and newborn piglets
M. Natsuhori, M. Shimoda and E. Kokue
Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan. ms@cc.tuat.ac.jp
Plasma folates tetrahydrofolate (THF) and N5-methyltetrahydrofolate (5MF)
were determined in nongestating, gestating, and lactating sows (2 to 4 yr
old, 2-6 parities, n = 88) and in newborn, growing, and finishing pigs (0
to 158 days old, n = 191) with the use of high-performance liquid
chromatography with an electrochemical detector. Plasma folates after folic
acid injection (1 mg/kg iv) were also monitored in 2-day-, 2-wk-, and
2-mo-old pigs. In sows, plasma folates decreased significantly as pregnancy
advanced. This was mainly due to the decrease of THF, which must be caused
by the folate supply from the maternal body to the fetuses. In newborn
piglets, levels of "total" plasma folates were much higher than those in
adults (nongestating sows), and 5MF was the major folate content. This
result may be related to the observation that, after folic acid injection,
newborn piglets showed much higher metabolic activity of folic acid to 5MF
than adults. Rapid and drastic decrease of plasma folate was observed
during nursing in piglets, which is considered to be associated with the
decrease of the metabolic activity of folic acid and rapid expansion of
body volume together with negative folate intake during the nursing period.
