Estrogen receptor found in the facial nucleus of the newborn rat is suppressed by exogenous estrogen: immuno- and in situ hybridization histochemical studies.
Expression of the messenger RNA coding estrogen receptor (ER-mRNA) was detected in the ventromedial subnucleus of the facial nucleus of the newborn rat by in situ hybridization histochemistry (ISHH). The hybridization signal in this subnucleus increased from 1 to 6 days of age, then decreased at 11 days. By immunohistochemistry (IHC) using an antiserum which detects estrogen receptor (ER) specifically, immunopositive signals were also detected in the same subnucleus of the adjacent sections. On the other hand, neither of these signals were encountered in the same subnucleus of the adult rat. Thus, the present result extend our previous work (Yokosuka and Hayashi, 1992) showing that the expression of the ER in the facial nucleus is transient. A sex difference in the expression of ER molecules was not apparent by ISHH and IHC. Moreover, daily injections of estradiol from the day of birth suppressed the expression of ER in the subnucleus at 6 and 11 days of age. Thus, as has been detected in the mediobasal hypothalamus, ER-mRNA was revealed to be down-regulated by estrogen.
Department of Anatomy and Embryology, Tokyo Metropolitan Institute for Neuroscience, Japan.
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Orikasa
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Okamura
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Hayashi
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D004958:Estradiol / Q000494:pharmacology*; D005154:Facial Nerve / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015347:RNA Probes; D051381:Rats; D017207:Rats, Sprague-Dawley; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D012727:Sex Characteristics
D015347:RNA Probes; D011960:Receptors, Estrogen; D004958:Estradiol