dc.contributor.author | Duncan, PJ | |
dc.contributor.author | Tabak, J | |
dc.contributor.author | Ruth, P | |
dc.contributor.author | Bertram, R | |
dc.contributor.author | Shipston, MJ | |
dc.date.accessioned | 2018-02-22T08:40:54Z | |
dc.date.issued | 2016-08-01 | |
dc.description.abstract | Corticotroph cells from the anterior pituitary are an integral component of the hypothalamic-pituitary-adrenal (HPA) axis, which governs the neuroendocrine response to stress. Corticotrophs are electrically excitable and fire spontaneous single-spike action potentials and also display secretagogue-induced bursting behavior. The HPA axis function is dependent on effective negative feedback in which elevated plasma glucocorticoids result in inhibition at the level of both the pituitary and the hypothalamus. In this study, we have used an electrophysiological approach coupled with mathematical modeling to investigate the regulation of spontaneous and CRH/arginine vasopressin-induced activity of corticotrophs by glucocorticoids. We reveal that pretreatment of corticotrophs with 100 nM corticosterone (CORT; 90 and 150 min) reduces spontaneous activity and prevents a transition from spiking to bursting after CRH/arginine vasopressin stimulation. In addition, previous studies have identified a role for large-conductance calcium- and voltage-activated potassium (BK) channels in the generation of secretagogue-induced bursting in corticotrophs. Using the dynamic clamp technique, we demonstrated that CRH-induced bursting can be switched to spiking by subtracting a fast BK current, whereas the addition of a fast BK current can induce bursting in CORT-treated cells. In addition, recordings from BK knockout mice (BK(-/-)) revealed that CORT can also inhibit excitability through BK-independent mechanisms to control spike frequency. Thus, we have established that glucocorticoids can modulate multiple properties of corticotroph electrical excitability through both BK-dependent and BK-independent mechanisms. | en_GB |
dc.description.sponsorship | This work was supported by Grant 082407 from the Wellcome
Trust (to M.J.S. and P.R.), Grant J008893 from the Medical
Research Council (to M.J.S.), and Grant DK43200 from the
National Institutes of Health (to R.B.). P.J.D. was supported by
a Medical Reseach Council PhD studentship in the College of
Medicine and Veterinary Medicine, University of Edinburgh. | en_GB |
dc.identifier.citation | Vol. 157, pp. 3108 - 3121 | en_GB |
dc.identifier.doi | 10.1210/en.2016-1115 | |
dc.identifier.uri | http://hdl.handle.net/10871/31617 | |
dc.language.iso | en | en_GB |
dc.publisher | Oxford University Press | en_GB |
dc.relation.url | https://www.ncbi.nlm.nih.gov/pubmed/27254001 | en_GB |
dc.rights | This article has been published under the terms of the Creative Commons Attribution
License (CC-BY; https://creativecommons.org/licenses/by/4.0/), which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source
are credited. Copyright for this article is retained by the author(s). | en_GB |
dc.title | Glucocorticoids inhibit CRH/AVP-evoked bursting activity of male murine anterior pituitary corticotrophs. | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2018-02-22T08:40:54Z | |
dc.identifier.issn | 0013-7227 | |
exeter.place-of-publication | United States | en_GB |
dc.description | This is the final version of the article. Available on open access from the publisher via the DOI in this record. | en_GB |
dc.identifier.journal | Endocrinology | en_GB |