Dual action of GABAA receptors on the secretory process of melanotrophs of Xenopus laevis

Jenks, B. G., De Koning, H. P. , Valentijn, K. and Roubos, E. W. (1993) Dual action of GABAA receptors on the secretory process of melanotrophs of Xenopus laevis. Neuroendocrinology, 58(1), pp. 80-85. (doi: 10.1159/000126516)

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Publisher's URL: http://dx.doi.org/10.1159/000126516

Abstract

The effects of GABA<sub>a</sub> receptor activation on the secretion of α-melanocyte-stimulating hormone (α-MSH) from the superfused pars intermedia of the amphibian Xenopus laeviswereexamined. The GABA<sub>a</sub> receptor agonist isoguvacine inhibited secretion of α-MSH from the pars intermedia, an action completely antagonized by the chloride channel blocker picrotoxin. Isoguvacine stimulated secretion from picrotoxin-treated tissue. Both effects were blocked by the GABA<sub>A</sub> receptor antagonist bicuculline, indicating that it is a specific action via the GABA<sub>A</sub> receptor. We conclude that, besides the inhibitory chloride channel, there is a stimulatory signaling property associated with the GABA<sub>A</sub> receptor. Isoguvacine stimulated the production of c-AMP, an action that was not blocked by picrotoxin. This suggests that the stimulatory mechanism of the GABA<sub>A</sub> receptor involves, directly or indirectly, the generation of c-AMP.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:De Koning, Professor Harry
Authors: Jenks, B. G., De Koning, H. P., Valentijn, K., and Roubos, E. W.
College/School:College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Neuroendocrinology
Publisher:Karger
ISSN:0028-3835
ISSN (Online):1423-0194

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