Pregnancy, xanthurenic acid excretion

Similar results were observed, using a different amount of DL-trypto-phan, in the xanthurenuria of women at the end of normal pregnancy (E3). However, in one investigation, of eight women well advanced in pregnancy, only one excreted excessive xanthurenic acid after a test dose of DL-tryptophan and this pregnancy was complicated by disease (H5). The excessive excretion in this case was reduced with pyridoxine. 

According to Sue (SIO), blood poisoning during pregnancy placed a stress on the supply of pyridoxine by reason of excess protein metabolism. This fact, together with the presence of elevated amounts of histidine and histamine, inhibited the action of vitamin Bb, and caused excretion of large quantities of xanthurenic acid. 

Total and % Excretion of Kynubenic and Xanthurenic Acids by 18 Pregnant Women AT Different Stages of Pregnancy after Tryptophan Loading ... 

Brown et al. (B25) confirmed the results of Coppini and Camurri (C9) on excretion of kynurenic and xanthurenic acids and, at the same time, examined the excretion of other tryptophan metabolites. Their data indicate that the high levels of all urinary metabolites excreted by pregnant subjects were lowered by pyridoxine administration. It must be remembered that the requirement for pyridoxine in pregnancy varies in the different animal species (C6). It was also found that the levels of pyridoxine in the fetal blood are elevated whereas those of maternal blood decrease (GIO). 

Sprince, H., Lowy, R. S., Folsome, C. E., and Behrman, J. S., Studies on the urinary excretion of xanthurenic acid during normal and abnormal pregnancy a survey of the excretion of xanthurenic acid in normal nonpregnant, normal pregnant, pre-eclamptic, and eclamptic women. Am. J. Obstet. Gynecol. 62, 84-92 (1951). 

Pregnancy results in an increase in the urinary excretion of xanthurenic acid (B21, S18, VI, Wl), 3-hydroxykynurenine, kynurenine, acetylkynu-renine, 3-hydroxyanthranilic acid, 2-pyridone, and N -methylnicotina-mide (B21, H8, VI, Wl). Large doses of pyiidoxine may reduce the urine levels of these metabolites to or near the normal range (Wl, RIO). The findings in one study (H4), in which women early in preg-... 

Rose [305] reported the excretion of grossly increased amounts of xanthurenic acid in the urine of women taking combination products. A similar increase in tryptophan metabolites occurs in pregnancy and has been interpreted as indicating pyridoxine deficiency [306]. Dewhurst [307] subsequently postulated a causal connection between dysfunction of trytophan metabolism and certain types of depression. Winston [308] developed the concept further by suggesting that depression from oral contraceptive medication be treated with pyridoxine. Price and Toseland [309] have proposed routine inclusion of pyridoxine in oral contraceptive preparations. Developments will be awaited with interest. 

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