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Published on: October 24, 2018
Physiological changes in rat hypothalamic CRF: circadian, stress and steroid suppression
Peptides
|September 1, 1982
Summary
Hypothalamic corticotropin-releasing factor (CRF) levels decrease in the evening and after dexamethasone administration in rats. Stress did not alter CRF levels, suggesting handling stress may influence results.
Area of Science:
- Neuroendocrinology
- Physiology
Background:
- The hypothalamic-pituitary-adrenal (HPA) axis regulates stress response.
- Corticotropin-releasing factor (CRF) is a key peptide in the HPA axis.
Purpose of the Study:
- To investigate the regulation of hypothalamic CRF-like immunoreactivity.
- To assess the impact of dexamethasone and ether stress on CRF levels in rats.
Main Methods:
- Measurement of hypothalamic CRF-like immunoreactivity in male rats.
- Assessment of plasma corticosterone levels.
- Administration of dexamethasone and exposure to ether stress.
Main Results:
- Plasma corticosterone showed circadian rhythm, suppressed by dexamethasone, and increased by ether stress.
- Hypothalamic CRF-like immunoreactivity decreased in the p.m. and after dexamethasone.
- No significant change in hypothalamic CRF-like immunoreactivity was observed after ether stress.
Conclusions:
- Hypothalamic CRF release increases in the p.m. and synthesis decreases after dexamethasone.
- Handling stress might mask CRF changes during ether stress.
- Hypothalamic CRF is physiologically significant and responsive to HPA axis modulation.
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