The CRF-related peptide sauvagine stimulates and the GABA_B receptor agonist baclofen inhibits cyclic-AMP production in melanotrope cells of Xenopus laevis

Jenks, B.G., van Zoest, I.D., De Koning, H.P. , Leenders, H.J. and Roubos, E.W. (1991) The CRF-related peptide sauvagine stimulates and the GABA_B receptor agonist baclofen inhibits cyclic-AMP production in melanotrope cells of Xenopus laevis. Life Sciences, 48(17), pp. 1633-1637. (doi: 10.1016/0024-3205(91)90123-S)

Abstract

Release of α-MSH from the pars intermedia melanotrope cells of <i>Xenopus laevis</i> is regulated by various classical neurotransmitters and neuropeptides. We have examined the effect of two of these regulatory substances, the neurotransmitter GABA and the CRF-related peptide sauvagine, on the adenylate cyclase system of the melanotrope cells. Sauvagine treatment, which stimulates α-MSH release, lead to an elevation in the level of cyclic-AMP, an effect which was potentiated by cholera toxin. Treatment with baclofen, a GABA_B receptor agonist, gave a pertussis toxin-sensitive decrease in the cyclic-AMP level and an inhibition of α-MSH release. We conclude that sauvagine stimulates α-MSH secretion through activation of adenylate cyclase and that GABA_B receptor activation inhibits secretion through inhibition of cyclic-AMP production. Baclofen treatment sensitized melanotrope cells to the stimulatory action of 8-bromo-cyclic-AMP on the secretion of α-MSH. This observation supports the conclusion that GABA_B receptor activation inhibits cyclic-AMP production.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: De Koning, Professor Harry
• Authors: Jenks, B.G., van Zoest, I.D., De Koning, H.P., Leenders, H.J., and Roubos, E.W.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Life Sciences
• Publisher: Elsevier
• ISSN: 0024-3205
• ISSN (Online): 1879-0631