CHANGE IN BLOOD-LEVELS OF VITAMIN-B-6 DERIVATIVES IN PREGNANT AND LACTATING RATS

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.