The effects of estrogen and progesterone on plasma amino acids levels: evidence from change plasma amino acids levels during the menstrual cycle in women

This study aimed to investigate the influence of plasma free amino acids (PFAA) concentration changed during the menstrual cycle in women. In 21 healthy university students were recruited who have almost 28 days in menstrual cycle before 2 months diary and measured by basal body temperature. The subjects blood samples were collected in menstrual cycles; menstrual (the 3-5 days), follicular (the 8-11 days), ovulation, luteal-1(the 18-20 days), luteal-2(the 24-28days) among two menstrual cycles. The following 22 amino acids were measured by HPLC-ESI MS and meta-analysis; alanine (Ala), arginine (Arg), asparagine (Asn), cysteine (Cys), citrulline (Cit), glutamine (Gln), glycine (Gly), histidine (His), isoleucine (Ile), leucine (Leu), lysine (Lys), methionine (Met), Ornitine (Orn), phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), tryptophan (Trp), tyrosine (Tyr), valine (Val), aspartate (Asp) and glutamate (Glu). Furthermore, estrogen and progesterone were measured. Many mean PFAA (Gly, Ser, Pro, Thr, Orn, Gln, Arg, Cit, Tyr, Asn, Ala, Cys, Lys) at luteal were lower than that of other menstrual cycles. Furthermore many PFAA at luteal were significantly lower than that of follicular (p < 0.05). Many PFAA underwent influence of the menses cycle, and the changes in those amino acids were decrease in luteum mainly.