[Hormonal regulation of the menstrual cycle (author's transl)]

The menstrual cycle is regulated by a complex hormonal system with positive and negative feedback mechanisms and changes in sensitivity of peripheral tissues. Four concepts appear to be fundamental: -- regular, pulsatile secretion of LHR is necessary to the functioning of the system; -- regulation is to a great extent effected by the pituitary gland in response to changes in ovarian steroid levels; -- changes in ovarian steroid levels are due to regulatory changes in receptivity to pituitary hormones, as well as to variations in enzyme activities; -- at the periphery, changes in hormonal impacts are accompanied by modifications of receptivity to steroid hormones.