Oestrogen receptor beta-immunoreactivity in gonadotropin releasing hormone-expressing neurones: regulation by oestrogen.
Double-label immunohistochemistry was employed to establish whether immunoreactivity for the beta subtype of the oestrogen receptor (ER beta-IR) is present in gonadotropin releasing hormone (GnRH)-containing cells. In the immortalized GnRH cell line, GT1-7, almost all nuclei were immunoreactive for ER beta. In the preoptic area of ovariectomized rats, more than one-half of the GnRH neurones (52.0-63.5%) contained ER beta-IR within the nucleus; a smaller proportion of these neurones (5-10%) displayed a particularly intense nuclear signal for ER beta. The presence of ER beta-IR in the nuclei of GT1-7 cells and GnRH neurones is consistent with recent reports of ER beta mRNA in these cells. Oestrogen treatment reduced the percentage of GnRH neurones with detectable ER beta-IR. The range of signal intensity for ER beta and the incidence of the ER beta signal in GnRH neurones were comparable following double-label immunohistochemistry involving either bright field or fluorescent techniques. These findings raise the possibility that ER beta receptors mediate direct effects of oestrogen on GnRH neurones.
Kalló
I
I
Centre for Neuroscience Research, King's College London, London, UK. imre.kallo@kcl.ac.uk
Butler
J A
JA
Barkovics-Kalló
M
M
Goubillon
M L
ML
Coen
C W
CW
D000818:Animals; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism; D047629:Estrogen Receptor beta; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism*; D010052:Ovariectomy; D011301:Preoptic Area / Q000378:metabolism; D051381:Rats; D011960:Receptors, Estrogen / Q000037:antagonists & inhibitors / Q000378:metabolism*
D047629:Estrogen Receptor beta; D004967:Estrogens; D011960:Receptors, Estrogen; D007987:Gonadotropin-Releasing Hormone