Elsevier

Neuroscience

Volume 7, Issue 7, July 1982, Pages 1615-1622
Neuroscience

The gadolinium ion: A potent blocker of calcium channels and catecholamine release from cultured chromaffin cells

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Abstract

Gadolinium (Gd3+) is a trivalent ion of the lanthanide series which has a high charge density and a similar ionic radius to Ca2+. The effects of gadolinium ions on [3H]noradrenaline output and 45Ca fluxes during resting conditions and stimulation were investigated in cultured bovine chromaffin cells. Chromaffin cells isolated from bovine adrenal medullae were plated on collagen-coated dishes (106 cells/dish) in a medium containing 10% fetal calf serum. Seven-day-old cells were used in all studies.

Exposure of chromaffin cells to 0.05mM Gd3+ produced 80 ± 5% and 81 ± 4% inhibition of the secretory responses to 10−4M acetylcholine and 56 mM K+ respectively. Doubling of the extracellular concentration of Gd3+ produced an 87 ± 3% and 100 ± 2% inhibition of the acetylcholine-induced and K+-induced release of [ 3H]noradrenaline. Gd3+ (0.05 mM) also produced a parallel shift to the right in the dose-response relationship between extracellular Ca2+ concentrations and [ 3H]noradrenaline output during acetylcholine stimulation. This observation suggests a competitive antagonism between Ca2+ and Gd3+ in stimulus-secretion coupling.

Gd3+ (0.05 mM) was an effective inhibitor (92.3 ± 0.7%) of the uptake of 45Ca into chromaffin cells induced by a depolarizing concentration (56 mM) of K+. Furthermore, Gd3+ also inhibited the increase in both Ca2+ − Ca2+ exchange mechanism and [ 3H]noradrenaline output observed in chromaffin cells upon the reintroduction of Ca2+ into a Ca2+]-free incubation medium.

The results, which were obtained using low concentrations of Gd3+, indicate that gadolinium is a powerful inhibitor of the Ca2+ movements which are required for triggering amine release from chromaffin cells by different secretagogues. Moreover, the results also suggest that Gd3+ might be a useful tool for release and electrophysiological studies in other Ca2+-dependent systems.

References (36)

  • TrifaróJ.M. et al.

    Differential effects of concanavalin A on acetylcholine and potassium-evoked release of catecholamines from cultured chromaffin cells

    Neuroscience

    (1981,[object Object])
  • TrifaróJ.M. et al.

    Morphological characteristics and stimulus-secretion coupling in bovine adrenal chromaffin cell cultures

    Neuroscience

    (1980)
  • AguirreJ. et al.

    Effect of methoxyverapamil on the stimulation by Ca2+, Sr2+ and Ba2+ and on the inhibition by Mg2+ of catecholamine release from the adrenal medulla

    Br. J. Pharmac.

    (1979)
  • AguirreJ. et al.

    Calcium movements during the release of catecholamines from the adrenal medulla: effect of methoxyverapamil and external cations

    J. Physiol., Lond.

    (1977)
  • BorowitzJ.L.

    Effect of lanthanum on catecholamine release from adrenal medulla

    Life Sci.

    (1972)
  • BrandtB.L. et al.

    Action potentials in the rat chromaffin cell and effects of acctylcholine

    J. Physiol., Lond.

    (1976)
  • BresnahanS.J. et al.

    Mechanisms of La3+-induced adrenal catecholamine release

    Res. Comm. Chem. Path. Pharm.

    (1980)
  • BurridgeR. et al.

    Association of actin and myosin with secretory granule membranes

    Nature, Lond.

    (1975)
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