Expression of estrogen receptor alpha and beta genes in the mediobasal hypothalamus, pituitary and ovary during the canine estrous cycle.
Estrogen receptor alpha (ERalpha) and ERbeta mRNA levels were measured in the mediobasal hypothalamus, the anterior pituitary and the ovary of beagle bitches at various stages of the estrous cycle. With polymerase chain reaction analysis we detected ERbeta gene transcripts in all tissue samples. The levels of hypothalamic and pituitary ERalpha and beta mRNAs increased from mid anestrus to proestrus and declined thereafter. In the ovary, ERalpha mRNA levels increased from proestrus to diestrus and were positively correlated with plasma progesterone levels (r=0.62, P<0.01), whereas ERbeta mRNA levels increased from mid anestrus to proestrus and were positively correlated with plasma estradiol-17beta levels (r=0.73, P<0.001). These results suggest that the rise in hypothalamic and pituitary ERalpha and beta mRNAs is associated with termination of anestrus, and that increases in ovarian ERalpha and beta mRNAs may be involved in initiating development of the follicle or corpora lutea.
Hatoya
Shingo
S
Laboratory of Cell Pathobiology, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, 599-8531 Osaka, Japan.
Torii
Ryuzo
R
Kumagai
Daijiro
D
Sugiura
Kikuya
K
Kawate
Noritoshi
N
Tamada
Hiromichi
H
Sawada
Tsutomu
T
Inaba
Toshio
T
D000818:Animals; D004285:Dogs; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D030762:Estrous Cycle; D005260:Female; D007031:Hypothalamus / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger; D011960:Receptors, Estrogen