Pampillo M, Scimonelli T, Duvilanski BH, Celis ME, Seilicovich A, Lasaga M. The activation of metabotropic glutamate receptors differentially affects GABA and alpha-melanocyte stimulating hormone release from the hypothalamus and the posterior pituitary of male rats.
Neurosci Lett 2002;
327:95-8. [PMID:
12098644 DOI:
10.1016/s0304-3940(02)00386-5]
[Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The aim of the present study was to investigate the effect of metabotropic glutamate receptor (mGluR) activation on gamma-aminobutyric acid (GABA) and alpha-melanocyte stimulating hormone (alpha-MSH) release from hypothalamic fragments and posterior pituitaries. The actions of a number of subtype-selective mGluR agonists were monitored. A group I mGluR agonist, (S)-3-hydroxyphenylglycine (3-HPG; 0.5 mM), decreased K+-induced hypothalamic GABA release. (RS)-1-Aminoindan-1,5-dicarboxylic acid (AIDA), a specific group I mGluR antagonist (0.2 mM), blocked the effect of 3-HPG. (2S, 1'S, 2'S)-2-(Carboxycyclopropyl) glycine (L-CCG-I) and L-serine-O-phosphate (L-SOP; 0.01-1 mM), agonists of group II and III mGluRs, respectively, did not modify hypothalamic evoked GABA release. Group I mGluR activation decreased, whereas group III increased and group II induced no changes in GABA release from the posterior pituitary. 3-HPG (1 mM) and L-CCG-I (0.1 mM) decreased, whereas L-SOP (0.01-0.1 mM) did not change alpha-MSH release from hypothalamic fragments. No agonists of the three mGluR groups modified alpha-MSH release from the posterior pituitary. These results indicate that activation of mGluRs differentially affects GABA and alpha-MSH release from the hypothalamus and the posterior pituitary.
Collapse