The thapsigargin-sensitive intracellular Ca2+ pool is more important in plasma membrane Ca2+ entry than the IP3-sensitive intracellular Ca2+ pool in neuronal cell lines

TY - JOUR

T1 - The thapsigargin-sensitive intracellular Ca2+ pool is more important in plasma membrane Ca2+ entry than the IP3-sensitive intracellular Ca2+ pool in neuronal cell lines

AU - Takemura, H

AU - Ohshika, H

AU - Yokosawa, N

AU - Oguma, K

AU - Thastrup, Ole

PY - 1991

Y1 - 1991

N2 - In NG108-15 cells, bradykinin (BK) and thapsigargin (TG) caused transient increases in a cytosolic free Ca2+ concentration ([Ca2+]i), after which [Ca2+]i elevated by TG only declined to a higher, sustained level than an unstimulated level. In PC12 cells, carbachol (CCh) evoked a transient increase in [Ca2+]i followed by a sustained rise of [Ca2+]i, whereas [Ca2+]i elevated by TG almost maintained its higher level. In the absence of extracellular Ca2+, the sustained elevation of [Ca2+]i induced by each drug we used was abolished. In addition, the rise in [Ca2+]i stimulated by TG was less affected after CCh or BK, whereas CCh or BK caused no increase in [Ca2+]i after TG. TG neither increased cellular inositol phosphates nor modified the inositol phosphates format on stimulated by CCh or BK. We conclude that TG may release Ca2+ from both IP3-sensitive and -insensitive intracellular pools and that some kinds of signalling to link the intracellular Ca2+ pools and Ca2+ entry seem to exist in neuronal cells.

AB - In NG108-15 cells, bradykinin (BK) and thapsigargin (TG) caused transient increases in a cytosolic free Ca2+ concentration ([Ca2+]i), after which [Ca2+]i elevated by TG only declined to a higher, sustained level than an unstimulated level. In PC12 cells, carbachol (CCh) evoked a transient increase in [Ca2+]i followed by a sustained rise of [Ca2+]i, whereas [Ca2+]i elevated by TG almost maintained its higher level. In the absence of extracellular Ca2+, the sustained elevation of [Ca2+]i induced by each drug we used was abolished. In addition, the rise in [Ca2+]i stimulated by TG was less affected after CCh or BK, whereas CCh or BK caused no increase in [Ca2+]i after TG. TG neither increased cellular inositol phosphates nor modified the inositol phosphates format on stimulated by CCh or BK. We conclude that TG may release Ca2+ from both IP3-sensitive and -insensitive intracellular pools and that some kinds of signalling to link the intracellular Ca2+ pools and Ca2+ entry seem to exist in neuronal cells.

KW - Animals

KW - Biological Transport

KW - Bradykinin

KW - Calcium

KW - Calcium Channel Blockers

KW - Cell Line

KW - Cell Membrane

KW - Fluorescent Dyes

KW - Fura-2

KW - Glioma

KW - Inositol 1,4,5-Trisphosphate

KW - Inositol Phosphates

KW - Kinetics

KW - Neuroblastoma

KW - Nimodipine

KW - PC12 Cells

KW - Peptides, Cyclic

KW - Terpenes

KW - Thapsigargin

KW - omega-Conotoxins

M3 - Journal article

C2 - 1953794

SN - 0006-291X

VL - 180

SP - 1518

EP - 1526

JO - Biochemical and Biophysical Research Communications

JF - Biochemical and Biophysical Research Communications

IS - 3

ER -