H. Tsuge et al., CHANGE IN BLOOD-LEVELS OF VITAMIN-B-6 DERIVATIVES IN PREGNANT AND LACTATING RATS, Journal of nutritional science and vitaminology, 40(3), 1994, pp. 239-249
By using an HPLC method which we have developed, concentration changes
of vitamin B-6 derivatives in blood of pregnant and lactating rats we
re studied. PLP and PL were the main derivatives in plasma and erythro
cytes, and occasionally, PMP was found in the plasma of rats fed a nor
mal solid diet which contained 8.3 mg PN . HCl/kg diet. Upon pregnancy
, the plasma PLP concentration decreased significantly (p<0.01), where
as plasma PL tended to increase (p<0.05). PLP concentration in erythro
cytes tended to increase upon pregnancy. These results suggest that me
tabolism or utilization of vitamin B-6 is altered upon pregnancy and t
hat plasma PLP concentrations alone may not be a good indicator of nut
ritional status. Further confirmation was needed for the reliable dete
rmination of PMP because a large peak found at 7 min or so from erythr
ocyte samples under our analytical conditions was not converted to PIC
-P via PLP, after the sample was treated with glyoxylic acid and then
with KCN.