Ca2+ transients and Mn2+ entry in human neutrophils induced by thapsigargin
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Ca2+ transients and Mn2+ entry in human neutrophils induced by thapsigargin. / Foder, B; Scharff, O; Thastrup, Ole.
I: Cell Calcium, Bind 10, Nr. 7, 1989, s. 477-90.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Ca2+ transients and Mn2+ entry in human neutrophils induced by thapsigargin
AU - Foder, B
AU - Scharff, O
AU - Thastrup, Ole
PY - 1989
Y1 - 1989
N2 - Human neutrophils, preloaded with the fluorescent probe, Fura-2, were exposed to Ca2+-releasing agents. The monitored traces of fluorescence were transformed by computer to cytosolic Ca2+ concentration ([ Ca2+]i). Due to quenching of Fura-2, the addition of Mn2+ enabled us to compute the cytosolic concentration of total manganese ([Mn]i). The agents used were the novel Ca2+-mobilizing agent, thapsigargin (Tg), the chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP), and the divalent cation ionophore, A23187. The agents caused transient rises of [Ca2+]i and monotonous rises of [Mn]i, suggesting influx but no efflux of Mn2+. The rise time of [Ca2+]i and the time constants and magnitude of the apparent Mn2+ influx were strongly dependent on the sequence of addition of the agonist and Ca2+. Contrary to FMLP, Tg needed several minutes to exert its full effect on the rise of [Ca2+]i and on the influx of Mn2+, the latter being dependent on two phases, activation and partial inactivation. Pretreatment with phorbol 12-myristate 13-acetate (PMA) inhibited the responses of Tg, FMLP and A23187. For comparison, human red blood cells were tested. Contrary to A23187, Tg did not induce Ca2+ uptake in ATP-depleted red cells but increased the Ca2+ pump flux in intact red cells by 10%. The experimental data and computer simulations of the granulocyte data suggest that time-dependent changes of both passive Ca2+ flux into the cytosol and Ca2+ flux of the plasma membrane pump are involved in the transient [Ca2+]i response.
AB - Human neutrophils, preloaded with the fluorescent probe, Fura-2, were exposed to Ca2+-releasing agents. The monitored traces of fluorescence were transformed by computer to cytosolic Ca2+ concentration ([ Ca2+]i). Due to quenching of Fura-2, the addition of Mn2+ enabled us to compute the cytosolic concentration of total manganese ([Mn]i). The agents used were the novel Ca2+-mobilizing agent, thapsigargin (Tg), the chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP), and the divalent cation ionophore, A23187. The agents caused transient rises of [Ca2+]i and monotonous rises of [Mn]i, suggesting influx but no efflux of Mn2+. The rise time of [Ca2+]i and the time constants and magnitude of the apparent Mn2+ influx were strongly dependent on the sequence of addition of the agonist and Ca2+. Contrary to FMLP, Tg needed several minutes to exert its full effect on the rise of [Ca2+]i and on the influx of Mn2+, the latter being dependent on two phases, activation and partial inactivation. Pretreatment with phorbol 12-myristate 13-acetate (PMA) inhibited the responses of Tg, FMLP and A23187. For comparison, human red blood cells were tested. Contrary to A23187, Tg did not induce Ca2+ uptake in ATP-depleted red cells but increased the Ca2+ pump flux in intact red cells by 10%. The experimental data and computer simulations of the granulocyte data suggest that time-dependent changes of both passive Ca2+ flux into the cytosol and Ca2+ flux of the plasma membrane pump are involved in the transient [Ca2+]i response.
KW - Benzofurans
KW - Calcimycin
KW - Calcium
KW - Computer Simulation
KW - Erythrocytes
KW - Fluorescent Dyes
KW - Fura-2
KW - Homeostasis
KW - Humans
KW - Manganese
KW - Mathematics
KW - N-Formylmethionine Leucyl-Phenylalanine
KW - Neutrophils
KW - Plant Extracts
KW - Terpenes
KW - Tetradecanoylphorbol Acetate
KW - Thapsigargin
KW - Time Factors
U2 - 10.1016/0143-4160(89)90025-0
DO - 10.1016/0143-4160(89)90025-0
M3 - Journal article
C2 - 2515000
VL - 10
SP - 477
EP - 490
JO - Cell Calcium
JF - Cell Calcium
SN - 0143-4160
IS - 7
ER -
ID: 43350043