使用腦下垂體拮抗劑會增加腦下垂體對於GnRH之敏感性

使用GnRH antagonist腦下垂體拮抗劑一段時間後
會增加腦下垂體對於GnRH之敏感性
使的腦下垂體之LH分泌量增加

施打雌激素會回餽抑制腦下垂體分泌LH

http://humrep.oxfordjournals.org/content/25/6/1513.full

Figure 1

Balance of pituitary response. GnRH binds to the pituitary receptor causing initially a release of LH but also pituitary desensitization. After sustained binding it suppresses LH release. GnRH antagonist binds to the receptor, therefore GnRH can not bind: it blocks the LH release normally induced by GnRH and it may block the desensitizing effect of GnRH. Thus sustained binding of a GnRH antagonist may increase pituitary responsiveness to GnRH. Pituitary response (LH release) is the balance between stimulating (green color) and blocking effects (red color) and depends on the duration of GnRH and GnRH antagonist administration.

Figure 3

Median LH levels in post-menopausal women during GnRH antagonist treatment with or without estradiol administration.

Figure 5

Median LH area under curve before and after GnRH antagonist, with or without estradiol (E₂), in post-menopausal women.