%0 Journal Article
%T Long©\term patterns of urinary pyroglutamic acid in healthy humans
%A Richard S. Lord
%J Archive of "Physiological Reports".
%D 2016
%R 10.14814/phy2.12706
%X An investigation of human biological variation in urinary organic acids, including pyroglutamic acid along with 39 other compounds, was previously reported in which levels were determined for 8 weeks in healthy adult subjects. Here, unique, 4©\week©\long physiological trends for one of those compounds, pyroglutamic acid (PGA), are reported. When PGA levels for an individual rose above 40 ¦Ìg/mg creatinine, 4©\week downward progressions occurred until levels reached values near 15 ¦Ìg/mg creatinine and the pattern was reversed when levels for an individual were below that level in the early weeks of the study. The pattern was especially prominent among 8 of the 13 menstruating female subjects suggesting a possible association with metabolic stress of the menstrual cycle. However, it also appeared in 3 of the 8 male subjects where other sources of metabolic stress may be present. The menstrual association is consistent with estrogen©\mediated increase in oxidative stress. Since PGA is linked to glutathione turnover, the consistency of extreme values across all individuals displaying the pattern indicates that 15 and 40 ¦Ìg/mg creatinine may represent limits that trigger shifts in sulfur amino acid metabolism. This is the first observation of approximate month©\long cyclic responses in a glutathione©\related urinary marker in humans
%K Pyroglutamic acid
%K 5©\oxoproline
%K glutathione
%K physiological cycles
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816898/