Abstract
We have previously demonstrated expression of the proglucagon gene and synthesis and secretion of the proglucagon-derived peptides (PGDPs) in the fetal rat hypothalamus. The excitatory amino acid glutamate has been found to be a key regulator of hypothalamic neuroendocrine hormone secretion. Therefore, the effects of glutamate on hypothalamic PGDP secretion and synthesis were examined in the present study, using the hypothalamic culture model. Glutamate (10 microM) significantly stimulated PGDP secretion (P < 0.01), but had no effect on the total PGDP content of the cultures over 24 hr of incubation. Similarly, the metabotropic/ionotropic glutamate receptor agonist, quisqualic acid (10 microM) stimulated PGDP secretion only ( P < 0.05). In contrast, the ionotropic glutamate receptor agonist, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA; 10 microM) and antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 10 microM), had no effects on either secretion or content of the hypothalamic PGDPs. These findings suggest that excitatory amino acids, and glutamate in particular, regulate secretion but not synthesis of the PGDPs in the hypothalamus.
References
Jul 11, 1979·Histochemistry·I LorénJ Thorell
Sep 1, 1992·Neuroendocrinology·K M Stobie-Hayes, P L Brubaker
Sep 1, 1992·Brain Research Bulletin·F MoraE Blázquez
Mar 1, 1992·Trends in Neurosciences·A Baskys
Jan 1, 1992·Journal of Inherited Metabolic Disease·M WajnerE R Motta
Jun 1, 1991·Endocrinology·P L Brubaker
Feb 28, 1991·Nature·M MasuS Nakanishi
Nov 30, 1990·Science·A N van den PolF E Dudek
Jan 1, 1991·Endocrinology·D J DruckerP L Brubaker
Jan 1, 1990·Endocrinology·E Y LuiP L Brubaker
Nov 1, 1990·Endocrinology·Y C LeeD J Drucker
Jul 1, 1988·Endocrinology·P L Brubaker
Jun 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·D J Drucker, P L Brubaker
Jan 1, 1989·Neuroscience·R B MeekerJ N Hayward
Apr 1, 1989·Brain : a Journal of Neurology·G Goldenberg
Jun 1, 1989·Endocrinology·P L BrubakerD J Drucker
Nov 20, 1989·Brain Research·B KreymannS R Bloom
Sep 1, 1985·Endocrinology·D G PipeleersM Van de Winkel
Sep 1, 1987·Endocrinology·I ShimizuK Shima
May 22, 1988·The Journal of Comparative Neurology·S L JinP K Lund
Jan 1, 1986·The Biochemical Journal·C S HiiS L Howell
May 1, 1987·Endocrinology·P L Brubaker, M Vranic
Dec 3, 1984·FEBS Letters·N M Hoosein, R S Gurd
Feb 13, 1984·Brain Research·M A GhateiL O Uttenthal
Jan 1, 1984·Progress in Neurobiology·M Palkovits
Mar 1, 1984·Brain : a Journal of Neurology·J H AartsA J Wilkins
Sep 1, 1983·Neuroendocrinology·E ArnauldL P Renaud
Oct 1, 1980·Proceedings of the National Academy of Sciences of the United States of America·H TagerR J Dinerstein
Jan 1, 1993·Trends in Pharmacological Sciences·D D Schoepp, P J Conn
Jun 11, 1993·European Journal of Pharmacology·G BertrandJ Bockaert
Dec 7, 1993·Biochemistry·L S Kappen, I H Goldberg
Nov 1, 1993·Molecular and Cellular Biology·C P MillerJ F Habener
Nov 1, 1995·Physical Review. B, Condensed Matter·T KohmotoM Kaburagi