We have measured menstrual blood loss (MBL) in 56 women with dysfuncti
onal uterine bleeding and in 38 women with normal MBL and also estimat
ed histamine and mast cell counts in the myometrium, myometrial/endome
trial border and endometrium following hysterectomies. Our results sug
gest that excessive menstrual bleeding is associated with mast cell de
granulation and histamine release from the uterus.