Central activin administration modulates corticotropin-releasing hormone and adrenocorticotropin secretion
Research output: Contribution to journal › Journal article › Research › peer-review
A broad and diffuse neuronal network conveys information reflecting the state of the internal and external environment to the neurosecretory hypothalamus. Recently, we identified an inhibin-βA- (IβA) immunoreactive terminal field within the CRF-rich portion of the dorsomedial paraventricular nucleus which originates from a cell group in the commissural portion of the nucleus of the solitary tract (NTS). The NTS receives baroreceptor input, somatosensory input via the spino- solitary tract, and sensory information from the oral, thoracic, and abdominal cavities and, thus, is positioned to serve as a primary relay for visceral sensory inputs to neurons critical to the function of the hypothalamic-pituitary-adrenal (HPA) axis. Although these NTS cells contain multiple putative transmitters, we present evidence that activin, an inhibin-/SA dimer, plays a modulatory role in HPA axis function via facilitation of CRF release. First, intraventricular injection of activin-A (0-3 nmol), but not the related inhibin heterodimer, evoked dose-related 1.7- to 2.8-fold elevations of circulating ACTH levels in male rats. Second, analysis of hypophysial-portal plasma after bilateral paraventricular nucleus microinfusion of activin-A revealed a dose-related facilitation of CRF secretion up to 4-fold above preinjection levels which was unaccompanied by changes in arginine vasopressin levels. Finally, activin-A also enhanced CRF secretion from neonatal hypothalamic cells in primary culture with an EC50 dose of approximately 0.25 nM. Overall, these observations provide evidence of both an anatomical and a pharmacological substrate for activin-mediated central modu-lation of HPA axis function.
Original language | English |
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Journal | Endocrinology |
Volume | 128 |
Issue number | 5 |
Pages (from-to) | 2520-2525 |
Number of pages | 6 |
ISSN | 0013-7227 |
DOIs | |
Publication status | Published - 1 May 1991 |
ID: 283517099