Growth hormone-releasing hormone neurons in the anestrus cat do not express progesterone receptors.
Ovarian steroids have been implicated in the regulation of growth hormone (GH) secretion in several species and increased progesterone secretion has been associated with elevated circulating GH levels in the cat. These high GH concentrations may be due, at least in part, to a direct action of progesterone on growth hormone-releasing hormone (GHRH) neurons. Using standard immunocytochemical methods coupled to high-temperature antigen retrieval, the objective of this study was to determine whether progesterone receptors were colocalized in GHRH neurons of the anestrus cat. GHRH perikarya were restricted to the infundibular nucleus and the ventral ventromedial nucleus and although frequently surrounded by numerous progesterone receptor-immunoreactive cells, none was colocalized. This study, therefore, provides evidence that, in the adult anestrus female cat, GHRH neurons do not express nuclear progesterone receptors.
Skinner
Donal C
DC
Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA. dcs@uwyo.edu
Head
Sarah
S
Oliver
James
J
D000780:Anestrus / Q000502:physiology*; D000818:Animals; D002415:Cats; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D011980:Receptors, Progesterone / Q000032:analysis*
D011980:Receptors, Progesterone; D013007:Growth Hormone-Releasing Hormone