Voltage-gated calcium channels and nonvoltage-gated calcium uptake pathways in the rat incisor odontoblast plasma membrane.
AuthorsLundgren T, Linde A
JournalCalcif Tissue Int
PubMed ID9030484
'Odontoblasts participate actively in the transport and accumulation of Ca2+ ions to the mineralization front during dentinogenesis. These cells are known to carry membrane-bound ATP-driven pumps and Na+/Ca2+ antiports for Ca2+ extrusion, but little is known about Ca2+ influx mechanisms into these cells. It has been shown that the administration ... More
Meiosis reinitiation in Ruditapes philippinarum (Mollusca): involvement of L-calcium channels in the release of metaphase I block.
AuthorsMoreau M, Leclerc C, Guerrier P
JournalZygote
PubMed ID8913029
'Prophase-arrested oocytes of Ruditapes philippinarum cannot be fertilised or stimulated by excess KCl, in contrast to the situation found in other bivalve species such as Barnea and Spisula. However, these oocytes can be triggered to reinitiate meiosis following treatment by serotonin or several pharmacological agents (calcium ionophores, thapsigargin, weak bases) ... More
Evidence for an external location of the dihydropyridine agonist receptor site on smooth muscle and skeletal muscle calcium channels.
AuthorsStrübing C, Hering S, Glossmann H
JournalBr J Pharmacol
PubMed ID7683566
'1. The location of the binding domain for agonist dihydropyridines (DHP) has been studied by comparing the action of (+)-202,791 and (-)-Bay K 8644 on Ba2+ currents (IBa) in whole cell patch clamp experiments. Drug effects were examined upon internal and external (extracellular) application in A7r5 smooth muscle cells and ... More
Ca2+ uptake through voltage-gated L-type Ca2+ channels by polarized enterocytes from Atlantic cod Gadus morhua.
AuthorsLarsson D, Lundgren T, Sundell K
JournalJ Membr Biol
PubMed ID9691116
'The presence and localization of voltage-gated Ca2+ channels of L-type were investigated in intestinal cells of the Atlantic cod. Enterocytes were loaded with the fluorescent Ca2+ probe, fure-2/AM and changes in intracellular Ca2+ concentrations ([Ca2+]i) were measured, in cell suspensions, in the presence of high potassium levels (100 mm), BAY ... More
In vivo labelling of L-type Ca2+ channels by fluorescent dihydropyridine: correlation between ontogenesis of the channels and the acquisition of neural competence in ecotderm cells from Pleurodeles waltl embryos.
AuthorsLeclerc C, Duprat AM, Moreau M
JournalCell Calcium
PubMed ID7542570
'The ability of the ectodermal cells to be induced and to differentiate toward neural tissue, called neural competence, is acquired shortly before gastrulation and lost during late gastrula stages in Pleurodeles waltl embryos. We have examined ectodermal cells'' neural competence in relation to the evolution of the density of L-type ... More
Polar localization of a dihydropyridine receptor on living Fucus zygotes.
AuthorsShaw SL, Quatrano RS
JournalJ Cell Sci
PubMed ID8838657
We have used a fluorescently-labeled dihydropyridine (FL-DHP) to vitally stain living Fucus zygotes during the establishment of cell polarity. Localization of FL-DHP is primarily at the plasma membrane and FL-DHP binding is competitively blocked by an unlabeled dihydropyridine. Distribution of FL-DHP is initially symmetrical before fixation of the polar axis, ... More
In vivo labeling of L-type Ca2+ channels by fluorescent dihydropyridines: evidence for a functional, extracellular heparin-binding site.
AuthorsKnaus HG, Moshammer T, Friedrich K, Kang HC, Haugland RP, Glossman H
JournalProc Natl Acad Sci U S A
PubMed ID1314393
We have synthesized and characterized fluorescently labeled dihydropyridines (DHPs) as probes for L-type Ca2+ channels. Racemic as well as (+)- and (-)-1,4-dihydro- 2,6-dimethyl-4-(2-trifluoromethylphenyl)-3,5-pyridinecarboxylic acid 2-(aminoethyl)ethyl ester hydrochlorides were coupled to boron dipyrromethane (Bodipy) derivatives. (4,4-Difluoro-5,7-dimethyl-4-bora-3a,4a-diaza)-3- (s-indacene)propionic acid (DMBodipy)-DHP and (4,4-difluoro-7-styryl-4-bora-3a,4a-diaza)-3-(s-indacene+ ++)propionic acid (STBodipy)-DHP have Kd values in the nanomolar range ... More
Limited plasticity of mesenchymal stem cells cocultured with adult cardiomyocytes.
AuthorsGallo MP, Ramella R, Alloatti G, Penna C, Pagliaro P, Marcantoni A, Bonafé F, Losano G, Levi R
JournalJ Cell Biochem
PubMed ID16888800
In order to assess, in a controlled in vitro model, the differentiation potential of adult bone marrow derived stem cells we have developed a coculture procedure using adult rat cardiomyocytes and mesenchymal stem cells (MSCs) from transgenic GFP positive rats. We investigated in the cocultured MSCs the time course of ... More