Abstract
Depolarizing 1-s pulses to 0 mV from a holding potential of −70 mV, induced whole-cell currents through Ca2+ channels (I Ca) in patch-clamped cat adrenal medulla chromaffin cells. The dihydropyridine (DHP) furnidipine (3 μM) reduced the peak current by 47% and the late current by 80%. ω-Conotoxin GVIA (CgTx, 1 μM) reduced the peak I Ca by 42% and the late I Ca by 55%. Pulses (10 s duration) with 70 mM K+/2.5 mM Ca2+ solution (70 K+/2.5 Ca2+), applied to single fura-2-loaded cat chromaffin cells increased the cytosolic Ca2+ concentration ([Ca2+]i from 0.1 to 2.21 μM; this increase was reduced by 43.7% by furnidipine and by 42.5% by CgTx. In the perfused cat adrenal gland, secretion evoked by 10-s pulses of 70 K+/2.5 Ca2+ was reduced by 25% by CgTx and by 96% by furnidipine. Similar results were obtained when secretion from superfused isolated cat adrenal chromaffin cells was studied and when using a tenfold lower [Ca2+]o. The results are compatible with the existence of DHP-sensitive (L-type) as well as CgTx-sensitive (N-type) voltage-dependent Ca2+ channels in cat chromaffin cells. It seems, howevever, that though extracellular Ca2+ entry through both channel types leads to similar increments of averaged [Ca2+]i, the control of catecholamine release is dominated only by Ca2+ entering through L-type Ca2+ channels. This supports the idea of a preferential segregation of L-type Ca2+ channels to localized “hot spots” in the plasmalemma of chromaffin cells where exocytosis occurs.
Similar content being viewed by others
References
Alajarin R, Alvarez-Builla J, Vaquero JJ, Sunkel C, Fau de Casa-Juana M, Statkow PR, Sanz-Aparicio J (1993) Synthesis and chromatographic separation of the stereoisomers of furnidipine. Tetrahedron Asymmetry 4:617–620
Albillos A, Artalejo AR, López MG, Gandía L, García AG, Carbone E (1994) Calcium channel subtypes in cat chromaffin cells. J Physiol (Lond) (in press)
Artalejo CR, García AG, Aunis D (1987) Chromaffin cell calcium channel kinetics measured isotopically through fast calcium, strontium and barium fluxes. J Biol Chem 262:915–927
Artalejo CR, Dahmer MK, Perlman RL, Fox AP (1991) Two types of Ca2+ currents are found in bovine chromaffin cells: facilitation is due to the recruitment of one type. J Physiol (Lond) 432:681–707
Artalejo CR, Mogul DJ, Perlman RL, Fox AP (1991) Three types of bovine chromaffin cell Ca2+ channels: facilitation increase the opening probability of a 27 pS channel. J Physiol (Lond) 444:213–240
Artalejo CR, Perlman RL, Fox AP (1992) ω-Conotoxin GVIA blocks a Ca2+ current in bovine chromaffin cells that is not of the “classic” N-type. Neuron 8:85–95
Augustine GJ, Neher E (1992) Calcium requirements for secretion in bovine chromaffin cells. J Physiol (Lond) 450:247–271
Bading H, Ginty DD, Greenberg ME (1992) Regulation of gene expression in hippocampal neurons by distinct calcium signalling pathways. Science 260:181–186
Ballesta JJ, Palmero M, Hidalgo MJ, Gutierrez LM, Reig JA, Viniegra S, García AG (1989) Separate binding and functional sites for ω-conotoxin and nitrendipine suggest two types of calcium channels in bovine chromaffin cells. J Neurochem 53:1050–1056
Borges R, Sala F, García AG (1986) Continuous monitoring of catecholamine release from perfused cat adrenals. J Neurosci Methods 16:389–400
Bossu JL, De Waard M, Feltz A (1991) Inactivation characteristics reveal two calcium currents in adult bovine chromaffin cells. J Physiol (Lond) 437:603–620
Bossu JL, De Waard M, Feltz A (1991) Two types of calcium channels are expressed in adult bovine chromaffin cells. J Physiol (Lond) 437:621–634
Calvo S, Granja R, González-García C, Ceña V (1993) Role of calcium and membrane potential on catecholamine secretion from bovine chromaffin cells. Seventh international symposium on chromaffin cell biology and pharmacology. In: Trifaró JM (ed) University of Ottawa, Ottawa, Canada, p 51
Carbone E, Sher E, Clementi F (1990) Ca currents in human neuroblastoma IMR32 cells: kinetics, permeability and pharmacology. Pflügers Arch 416:170–179
Castillo CJF, Fonteríz RI, López MG, Rosenheck K, García AG (1989) (+)PN200-110 and ouabain binding sites in purified bovine adrenomedullary plasma membranes and chromaffin cells. J Neurochem 53:1442–1449
Clasbrummel B, Osswald H, Illes P (1989) Inhibition of noradrenaline release by ω-conotoxin GVIA in the rat tail artery. Br J Pharmacol 96:101–110
Cohen CJ, McCarthy RT (1987) Nimodipine block of calcium channels in rat anterior pituitary cells. J Physiol (Lond) 387:195–225
Gandía L, Albillos A, García AG (1993) Bovine chromaffin cells possess FTX-sensitive calcium channels. Biochem Biophys Res Commun 194:671–676
García AG, Hernández M, Horga JF, Sánchez-García P (1980) On the release of catecholamines and dopamine beta-hydroxylase evoked by ouabain in the perfused cat adrenal gland. Br J Pharmacol 68:571–583
García AG, Sala F, Reig JA, Viniegra S, Frias J, Fonteríz RI, Gandía L (1984) Dihydropyridine Bay-K-8644 activates chromaffin cell calcium channels. Nature 308:69–71
Grynkiewicz G, Poenie M, Tsien RY (1985) A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem 260:3440–3450
Hans M, Illes P, Takeda K (1990) The blocking effects of ω-conotoxin on Ca currents in bovine chromaffin cells. Neurosci Lett 114:63–68
Hamill OP, Marty A, Neher E, Sackmann B, Sigworth FJ (1981) Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflügers Arch 391:85–100
Heinemann C, von Rüden L, Chow RH, Neher E (1993) A two-step model of secretion control in neuroendocrine cells. Pflügers Arch 424:105–112
Hernández-Cruz A, Sala F, Adams PR (1990) Subcellular calcium transients visualized by confocal microscopy in a voltage-clamped vertebrate neurone. Science 247:858–862
Hirning LD, Fox AP, McCleskey EW, Olivera BM, Thayer SA, Miller RJ, Tsien RW (1988) Dominant role of N-type Ca2+ channels in evoked release of norepinephrine from sympathetic neurons. Science 239:57–61
Jiménez RR, López MG, Sancho C, Maroto R, García AG (1993) A component of the catecholamine secretory response in the bovine adrenal gland is resistant to dihydropyridine and ω-conotoxin. Biochem Biophys Res Commun 191:1278–1283
Llinás R, Sugimori M, Lin JW, Cherksey B (1989) Blocking and isolation of a calcium channel from neurons in mammals and cephalopods utilizing a toxin fraction (FTX) from funnelweb spider poison. Proc Natl Acad Sci USA 86:1689–1693
Llinás R, Sugimori M, Silver RB (1992) Microdomains of high calcium concentration in a presynaptic terminal. Science 256:677–679
Maggi CA, Patacchini R, Santicioli P, Lippe ITh, Giuliani S, Geppeti P, del Bianco E, Selleri S, Meli A (1988) The effect of conotoxin GVIA, a peptide modulator of the N-type voltage-sensitive calcium channels, on motor responses produced by activation of efferent and sensory nerves in mammalian smooth muscle. Naunyn-Schmiedeberg's Arch Pharmacol 338:107–113
Neher E (1989) Neuromuscular junction. In: Sellin LC, Liblius R, Thesleff S (eds) Elsevier, Amsterdam, pp 65–76
Rüden L von, Neher E (1993) A Ca-dependent early step in the release of catecholamines from adrenal chromaffin cells. Science 262:1061–1065
Sanguinetti MC, Kass RC (1984) Voltage-dependent block of calcium channel current in the calf purkinje fiber by dihydropyridine calcium channel antagonists. Circ Res 55:336–348
Schroeder TJ, Jankowski JA, Wightman M (1993) Flameetched carbon-fiber microelectrodes used to study the localization and kinetic time course of single exocytotic events. Seventh international symposium on chromaffin cell biology and pharmacology. In: Trifaró JM (ed) University of Ottawa, Ottawa, Canada, p 134
Swandulla D, Carbone E, Lux HD (1991) Do calcium channel classifications account for neuronal calcium channel diversity. Trends Neurosci 14:46–51
Tsien RW, Ellinor PT, Horne WA (1991) Molecular diversity of voltage-dependent Ca2+ channels. Trends Pharmacol Sci 12:349–354
Uceda G, Artalejo AR, López MG, Abad F, Neher E, García AG (1992) Ca2+-activated K+ channels modulate muscarinic secretion in cat chromaffin cells. J Physiol (Lond) 454:213–230
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
López, M.G., Albillos, A., de la Fuente, M.T. et al. Localized L-type calcium channels control exocytosis in cat chromaffin cells. Pflügers Arch 427, 348–354 (1994). https://doi.org/10.1007/BF00374544
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00374544