Effect of estrogens on histidine metabolism

To confirm that estrogens may be responsible for an increase in histidine transamination, 37 menopausal women being treated with oral estrogens (potassium salt of estrone sulfate or equilenin) underwent histidine loading tests before and after treatment. There was a highly significant (p.001) increase in total "transamination metabolites" after estrogen treatment; there was no significant effect on creatinine excretion or urocanic acid output. Unusual chromatographic patterns were observed in nearly all of the urine specimens studied. In 2-solution paper electrophoresis, histidine streaked badly. This might have been due to some unknown substance excreted by the menopausal women.