title: Effects of estrogen and progesterone on the expression of connexin-36 mRNA in the suprachiasmatic nucleus of female rats.
abstract: To determine the effects of ovarian steroid hormones on gap junction communication in the suprachiasmatic nucleus (SCN), we examined the effects of estrogen and/or progesterone on the expression of connexin-36 mRNA in the SCN and cerebral cortex (CX) of female rats. Ovariectomized adult rats were injected with 20 microg 17beta-Estradiol or sesame oil 48 h before sacrifice and further injected with 1.5 mg progesterone or sesame oil 24 h before sacrifice. Northern blot revealed that estrogen significantly increased the expression of connexin-36 mRNA in the SCN and this increase was inhibited by progesterone. On the other hand, the connexin-36 mRNA level in the CX was not affected by estrogen or progesterone. These results suggest that the gap junction with connexin-36 in the SCN is specifically regulated by ovarian steroid hormones of female rats.
authors.affiliation: Department of Physiology, Yokohama City University School of Medicine, 236-0004, Yokohama, Japan. kazuyuki@dokkyomed.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Shinohara
authors.forename: T
authors.initials: T
authors.lastname: Funabashi
authors.forename: T J
authors.initials: TJ
authors.lastname: Nakamura
authors.forename: F
authors.initials: F
authors.lastname: Kimura
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D017630:Connexins / Q000235:genetics*; D004967:Estrogens / Q000378:metabolism / Q000494:pharmacology*; D004971:Estrus / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D017629:Gap Junctions / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000378:metabolism; D000097004:Gap Junction delta-2 Protein
chemical_list: D017630:Connexins; D004967:Estrogens; D005136:Eye Proteins; D011374:Progesterone; D012333:RNA, Messenger; D000097004:Gap Junction delta-2 Protein