Calcium influx is not required for TRH to elevate free cytoplasmic calcium in GH3 cells

Endocrinology
M C Gershengorn, C Thaw

Abstract

TRH stimulation of prolactin secretion is thought to be mediated by an elevation of free cytoplasmic Ca2+. However, whether TRH-induced influx of extracellular Ca2+ is required to elevate cytoplasmic Ca2+ remains controversial. We measured cytoplasmic free Ca2+ concentration in GH3 cells with an intracellularly trapped fluorescent indicator, Quin 2. In unstimulated cells incubated in medium containing 1.5 mM Ca2+, cytoplasmic free Ca2+ concentration was 118 +/- 18 nM (mean +/- SD). TRH (1 microM) caused a rapid transient elevation of free cytoplasmic Ca2+ to a level estimated to be at least 500 nM. High extracellular K+, which induces extracellular Ca2+ influx, caused an elevation of free cytoplasmic Ca2+ which was greater and longer in duration that that caused by TRH. When cells were incubated in medium containing 3 mM EGTA, the K+ depolarization-induced increase in free cytoplasmic Ca2+ was abolished. By contrast, the TRH-induced increase was not affected by incubating cells in medium with 3 mM EGTA, or high K+, or both; incubation of cells in medium with EGTA and high K+ abolishes the electrochemical driving force for Ca2+ influx. These data demonstrate that Ca2+ influx is not required for TRH-induced elevation of free cyto...Continue Reading

Citations

Jul 1, 1984·Molecular and Cellular Endocrinology·A M JuddR M MacLeod
Jun 1, 1984·Molecular and Cellular Endocrinology·K P Ray, M Wallis
Nov 1, 1985·Molecular and Cellular Endocrinology·D DelbekeP S Dannies
Dec 1, 1985·Molecular and Cellular Endocrinology·J S Ramsdell, A H Tashjian
May 1, 1985·Molecular and Cellular Endocrinology·K KoikeR M MacLeod
Jan 1, 1984·Kroc Foundation Series·R Y Tsien
Jan 31, 1989·Biochemical and Biophysical Research Communications·N SuzukiM Kano
Dec 1, 1996·Trends in Endocrinology and Metabolism : TEM·P M HinkleR Ashworth
Jul 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·A WeissJ Stobo
Oct 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·P M Hinkle, W J Phillips
Jun 1, 1985·Proceedings of the National Academy of Sciences of the United States of America·J M Dubinsky, G S Oxford
Jan 1, 1990·Journal of Endocrinological Investigation·A SpadaA Lania
Sep 30, 1985·Biochemical and Biophysical Research Communications·C S Sheela RaniJ B Field
Jan 1, 1989·Annals of the New York Academy of Sciences·M C Gershengorn
Sep 17, 1984·Biochemical and Biophysical Research Communications·D DelbekeH Rasmussen
Aug 31, 1990·Biochemical and Biophysical Research Communications·R H PaulssenK M Gautvik
Oct 30, 1990·Biochemical and Biophysical Research Communications·K Törnquist, P Stewen
Jul 31, 1987·Biochemical and Biophysical Research Communications·J A WaschekL E Eiden
Sep 5, 2006·American Journal of Physiology. Lung Cellular and Molecular Physiology·Andrea H RossiC William Davis
Jul 11, 1988·The American Journal of Physiology·J P Kile, M S Amoss
Jan 1, 1985·The American Journal of Physiology·S Ozawa
Feb 1, 1984·The American Journal of Physiology·K W Snowdowne, A B Borle
Jan 1, 1986·The American Journal of Physiology·J J EnyeartP M Hinkle
Apr 1, 1994·The American Journal of Physiology·S H Chueh, L S Kao
Sep 1, 1984·The American Journal of Physiology·C N ThawM C Gershengorn

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