Effects of estrogen and progesterone on the expression of connexin-36 mRNA in the suprachiasmatic nucleus of female rats.
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.
Shinohara
K
K
Department of Physiology, Yokohama City University School of Medicine, 236-0004, Yokohama, Japan. kazuyuki@dokkyomed.ac.jp
Funabashi
T
T
Nakamura
T J
TJ
Kimura
F
F
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
D017630:Connexins; D004967:Estrogens; D005136:Eye Proteins; D011374:Progesterone; D012333:RNA, Messenger; D000097004:Gap Junction delta-2 Protein