Estrogen negative feedback

Chongthammakun S, Teresawa E (1993) Negative feedback effects of estrogen on luteinizinghormone-releasinghormone release occur in pubertal, but not prepubertal, ovariectomized female rhesus monkeys. Endocrinology 132 735-743... 

There are also a few examples of positive feedback mechanisms in the endocrine system.25 43 In a positive feedback loop, rising concentrations of one hormone cause an increase in other hormones, which, in turn, facilitates increased production of the first hormone. The primary example of this type of feedback occurs in the female reproductive system, where low levels of estrogen production increase the release of pituitary hormones (LH, FSH).10 43 Increased LH and FSH then facilitate further estrogen production, which further increases pituitary hormone secretion, and so on (see Chapter 30). Positive feedback mechanisms are relatively rare, however, compared with negative feedback controls in the endocrine system. 

In summary, the menstrual cycle is primarily regulated by the interaction between pituitary and ovarian hormones. Also, releasing hormones from the hypothalamus plays a role in controlling female reproduction through their effects on LH and FSH release from the anterior pituitary.7 A complex series of positive and negative feedback mechanisms control the cyclic release of various female hormones.22,81,97 For instance, increased estrogen secretion in the follicular... 

Gonadotropin-releasing Works by negative feedback mechanisms to hormone drugs inhibit testosterone or estrogen production ... 

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