Calcium channel current in rat dental pulp cells

被引:17
作者
Davidson, RM
Guo, L
机构
[1] NYU, Coll Dent, Div Basic Sci, New York, NY 10010 USA
[2] NYU, Coll Dent, Dept Periodont, New York, NY 10010 USA
关键词
dental pulp; Ca2+ current; dihydropyridine; lanthanum; conotoxin; in vitro;
D O I
10.1007/s002320010011
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Voltage-gated Ca2+ currents in early-passage rat dental pulp cells were studied using whole-cell patch-clamp techniques. With Ba2+ as the charge carrier, two prominent inwardly-directed currents, I-f and I-s, were identified in these cells that could be distinguished on the basis of both kinetics and pharmacology. Is was activated by membrane depolarizations more positive than -30 mV, and displayed fast inactivation kinetics, while I, was activated by steeper depolarizations and inactivated more slowly. At peak current, time constants of inactivation for I-f and I-s were similar to 17 vs. similar to 631 msec. Both I-f and I-s could be blocked by lanthanum. By contrast, only I-s was sensitive to either Bay-K or nifedipine, a specific agonist and antagonist, respectively, of L-type Ca2+ channels. I, was also blocked by the peptide omega-Conotoxin GVIA. Taken together, results suggested that If was mediated by divalent cation flow through voltage-gated T-type Ca2+ channels, whereas I, was mediated by L- and N-type Ca2+ channels in the pulp cell membrane. The expression of these prominent, voltage-gated Ca2+ channels in a presumptive mineral-inductive phenotype suggests a functional significance vis a vis differentiation of dental pulp cells for the expression and secretion of matrix proteins, and/or formation of reparative dentin itself.
引用
收藏
页码:21 / 30
页数:10
相关论文
共 35 条
[1]   INVITRO MINERALIZATION OF A 3-DIMENSIONAL COLLAGEN MATRIX BY HUMAN DENTAL-PULP CELLS IN THE PRESENCE OF CHONDROITIN SULFATE [J].
BOUVIER, M ;
JOFFRE, A ;
MAGLOIRE, H .
ARCHIVES OF ORAL BIOLOGY, 1990, 35 (04) :301-309
[2]   CA CURRENTS IN HUMAN NEUROBLASTOMA IMR32 CELLS - KINETICS, PERMEABILITY AND PHARMACOLOGY [J].
CARBONE, E ;
SHER, E ;
CLEMENTI, F .
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY, 1990, 416 (1-2) :170-179
[3]   CHARACTERIZATION OF THE OMEGA-CONOTOXIN TARGET - EVIDENCE FOR TISSUE-SPECIFIC HETEROGENEITY IN CALCIUM-CHANNEL TYPES [J].
CRUZ, LJ ;
JOHNSON, DS ;
OLIVERA, BM .
BIOCHEMISTRY, 1987, 26 (03) :820-824
[4]   POTASSIUM CURRENTS IN CELLS DERIVED FROM HUMAN DENTAL-PULP [J].
DAVIDSON, RM .
ARCHIVES OF ORAL BIOLOGY, 1993, 38 (09) :803-811
[5]   NEURAL FORM OF VOLTAGE-DEPENDENT SODIUM CURRENT IN HUMAN CULTURED DENTAL-PULP CELLS [J].
DAVIDSON, RM .
ARCHIVES OF ORAL BIOLOGY, 1994, 39 (07) :613-620
[6]  
DENIS I, 1994, GROWTH REGULAT, V4, P123
[7]   MOLECULAR-CLONING OF THE ALPHA-1 SUBUNIT OF AN OMEGA-CONOTOXIN-SENSITIVE CALCIUM-CHANNEL [J].
DUBEL, SJ ;
STARR, TVB ;
HELL, J ;
AHLIJANIAN, MK ;
ENYEART, JJ ;
CATTERALL, WA ;
SNUTCH, TP .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1992, 89 (11) :5058-5062
[8]  
Duncan RL, 1998, SEMIN NEPHROL, V18, P178
[9]   Effects of extracellular calcium on the proliferation and differentiation of porcine osteoblasts in vitro [J].
Eklou-Kalonji, E ;
Denis, I ;
Lieberherr, M ;
Pointillart, A .
CELL AND TISSUE RESEARCH, 1998, 292 (01) :163-171
[10]   STRUCTURAL DETERMINANTS OF THE BLOCKADE OF N-TYPE CALCIUM CHANNELS BY A PEPTIDE NEUROTOXIN [J].
ELLINOR, PT ;
ZHANG, JF ;
HORNE, WA ;
TSIEN, RW .
NATURE, 1994, 372 (6503) :272-275