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Guanine nucleotides are potent secretagogues in permeabilized parathyroid cells
Journal article   Open access   Peer reviewed

Guanine nucleotides are potent secretagogues in permeabilized parathyroid cells

Marguerite Oetting, Meryl LeBoff, Linda Swiston, Joseph Preston and Edward Brown
FEBS letters, Vol.208(1), pp.99-104
1986
DOI: 10.1016/0014-5793(86)81540-X
PMID: 3770214
url
https://doi.org/10.1016/0014-5793(86)81540-XView
Published (Version of record) Open Access

Abstract

We studied the effects of GTP and its' analogues on PTH release in permeabilized parathyroid cells to assess their role in mediating the unusual inverse relationship between Ca 2+ and PTH release in intact parathyroid cells. Both 10-5 M GppNHp and GTPγS, nonhydrolysable analogues of GTP, produce up to an 8-fold enhancement of PTH release, which is dose-dependent. This effect is specific for GTP analogues as we could not mimic it with other nucleotides. 10 −3 M GDPβS, a nonhydrolysable GDP analogue, completely abolishes GppNHp-stimulated hormone release, providing further support for mediation of this effect by a guanine-nucleotide regulatory protein. In GppNHp-stimulated cells, PTH release is maximal at free [Ca 2+] less than 200 nM and progressively decreases as the free [Ca 2+] increases from 300 nM to 100 μM. These results suggest the presence of a guanine-nucleotide binding protein in the parathyroid cell that may play an important role in the regulation of PTH secretion by Ca 2+ and perhaps other secretagogues.
PTH release Permeabilized cell Guanine nucleotide Ca 2

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