Differential regulation by pregnenolone sulfate of intracellular Ca2+ increase by amino acids in primary cultured rat cortical neurons

Neurochemistry International
M TakebayashiS Yamawaki

Abstract

We investigated the effects of pregnenolone sulfate (PS) on the [Ca2+]i increase induced by gamma-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) using fluorescence imaging. PS inhibited the 50 microM GABA-induced increase in [Ca2+]i in a dose-dependent manner with an IC50 of 30 microM. The inhibitory effect of PS was apparent within 5 min and was in a non-competitive manner, suggesting that PS may act directly to the membrane level but indirectly to the GABA binding sites. Our previous study has already shown that the GABA-induced Ca2+ increase involves GABAA receptors and the similar pathway to a high K(+)-induced Ca2+ response (Takebayashi et al., 1996). Because 50 microM of PS could not inhibit a 25 mM K(+)-induced Ca2+ increase, it seems likely that the site of the inhibitory action of PS on the GABA-induced Ca2+ increase may be independent of the pathway of the high K(+)-induced Ca2+ response, but rather at GABAA receptor complex. In contrast, PS potentiated the 50 microM NMDA-induced increase in [Ca2+]i in a dose-dependent manner. The magnitude of the NMDA response was approximately doubled in the presence of 100 microM of PS. However, PS did not affect the acetylcholine(Ach)-induced increase in [Ca2+]i. Further...Continue Reading

References

Mar 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·J F FloodE Roberts
Dec 1, 1991·Trends in Neurosciences·E CherubiniY Ben-Ari
Oct 1, 1988·Trends in Neurosciences·R J Miller
Apr 1, 1989·Brain : a Journal of Neurology·M D RuggD N Brooks
Jul 22, 1985·Brain Research·M D MajewskaR L Eskay
Dec 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·Z Y HuE E Baulieu
Aug 1, 1994·Pharmacology, Biochemistry, and Behavior·C L Melchior, R F Ritzmann
Jan 1, 1993·Proceedings of the National Academy of Sciences of the United States of America·C MathurS Lieberman

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Citations

Mar 20, 2004·Pharmacology & Therapeutics·Sandeep KumarA Leslie Morrow
Aug 29, 2003·The Journal of Steroid Biochemistry and Molecular Biology·Monique ValléeMichel Le Moal
Sep 15, 2014·The Journal of Steroid Biochemistry and Molecular Biology·Maximillian A RogersTa-Yuan Chang
Jun 10, 2015·Journal of Receptor and Signal Transduction Research·Colin G Rousseaux, Stephanie F Greene
May 4, 2018·Psychopharmacology·Mairi Koulentaki, Elias Kouroumalis

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