Individual levels of plasma histidine-rich glycoprotein (HRG) during the normal menstrual cycle and in women on oral contraceptives low in oestrogen

Abstract

Histidine-rich glycoprotein (HRG), a 3.8 S-alpha 2-glycoprotein recently identified as a new fibrinolysis regulating protein, was determined by an electroimmunoassay in samples of plasma collected during one menstrual or hormone cycle in 15 young women and in 11 women using oral contraceptives with 30 micrograms ethinyl oestradiol and 150 micrograms levo-norgestrel. Distinct individual levels caused the within-group variations of plasma HRG to be larger than the individual variations. In the hormone group the plasma HRG levels were decreased to about 75% of the normal, while the fluctuations during the cycle were minor in both groups.