Norepinephrine but not epinephrine stimulates the release of corticotropin-releasing factor from in vitro superfused rat hypothalamus
✍ Scribed by G. Orliaguet; S. Mélik Parsadaniantz; V. Lenoir; P. Duval; B. Kerdelhué
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 543 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
To clarify the controversy concerning the role of catecholaminergic systems in regulating hypothalamic corticotropin-releasing factor (CRF) secretion, we assessed the direct effects of norepinephrine and epinephrine, alone and in association with mixed a and p antagonists on hypothalamic CRF secretion. An in vitro rat mediobasal hypothalamus perifusion system was used, in which CRF secretion from a single explant was evaluated by a specific radioimmunoassay. We found that norepinephrine stimulated CRF secretion, with peak effects at lo-' M concentration, whereas epinephrine had no effect on CRF secretion. The effect of norepinephrine was antagonised by the mixed CY antagonist phentolamine and by the mixed p antagonist propranolol.
We conclude that norepinephrine, but not epinephrine, stimulate hypothamic CRF secretion via a and p receptors. The data support the idea that the central noradrenergic systems are excitatory upon CRF-41 secretion when acting directly at the hypothalamic level. 1 )