Chronic estrogen exposure maintains elevated levels of progesterone receptor mRNA in guinea pig hypothalamus.
We performed in situ hybridization on hypothalamic sections from ovariectomized guinea pig using a cocktail of three 35S-labeled oligonucleotides complementary to mammalian progesterone receptor (PR) cDNA. PR mRNA was readily detected in hypothalamic neurons from guinea pigs pretreated with 17 beta-estradiol benzoate (E2B), but not from animals which did not receive supplemental E2B. The distribution of PR mRNA-containing cells corresponded well with previous localizations of PR in guinea pig. In contrast to earlier reports of E2B regulation of PR mRNA in rat hypothalamus, however, we found that PR mRNA remained elevated during chronic exposure to E2B (up to 10 days) in guinea pig.
Bayliss
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Department of Physiology, University of North Carolina, Chapel Hill 27599-7545.
Millhorn
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D000818:Animals; D001345:Autoradiography; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009693:Nucleic Acid Hybridization; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects / Q000235:genetics*; D011980:Receptors, Progesterone / Q000235:genetics*; D012016:Reference Values; D013462:Sulfur Radioisotopes
D015347:RNA Probes; D012333:RNA, Messenger; D011980:Receptors, Progesterone; D013462:Sulfur Radioisotopes; D004958:Estradiol; C010452:estradiol-17 beta-benzoate