Relaxin-induced expression of Fos in the forebrain of the late pregnant rat
| Autor: | Patricia A. Heine, Lynne R. Ross, Carol D. Jacobson, Lloyd L. Anderson, Shi Di |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
endocrine system
medicine.medical_specialty Endocrinology Diabetes and Metabolism Ovariectomy Oxytocin c-Fos Supraoptic nucleus Rats Sprague-Dawley Cellular and Molecular Neuroscience Endocrinology Prosencephalon Pregnancy Internal medicine medicine Animals Progesterone Relaxin Drug Implants biology Estradiol Endocrine and Autonomic Systems Immunohistochemistry Subfornical organ Rats medicine.anatomical_structure Hypothalamus Forebrain biology.protein Ovariectomized rat Female Proto-Oncogene Proteins c-fos Supraoptic Nucleus hormones hormone substitutes and hormone antagonists medicine.drug Paraventricular Hypothalamic Nucleus Subfornical Organ |
| Zdroj: | Neuroendocrinology. 66(1) |
| ISSN: | 0028-3835 |
| Popis: | Relaxin, administered parenterally, has been shown to increase the release of oxytocin (OT) into the circulation and increase the firing rate of OTergic neurons. The objective of the present study was to determine if relaxin administration can result in the expression of a transcription factor, suggesting that it alters transcriptional activity within OTergic neurons at the level of the hypothalamus. Primigravid rats were ovariectomized and a jugular cannula was inserted on day 11 of gestation (g11). Pregnancy was maintained by implanting 17 beta-estradiol and progesterone caplets subcutaneously at the time of ovariectomy. At gl9, rats were challenged with intravenous relaxin or isotonic saline and the brains were removed for study. Immunohistochemistry was performed on coronal brain sections, utilizing Fos as a marker of cellular activation. In the group receiving relaxin, Fos-like immunoreactivity (Fos-IR) was abundant only in the supraoptic (SON) and paraventricular nuclei (PVN) of the hypothalamus as well as in the subfornical organ (SFO). In contrast, Fos-IR in the group given isotonic saline was lacking in these three brain regions. A double label study using antibodies against Fos and OT demonstrated that a majority of the Fos-labeled cells in the hypothalamus were OTergic. Because Fos can act as a transcription factor, we interpret these data to indicate that transcription within OTergic cells is altered following relaxin administration, with abundant Fos-IR being limited to the SON and PVN of the hypothalamus and the SFO during late pregnancy in the rat. |
| Databáze: | OpenAIRE |
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