L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals
The involvement of the different types of voltage-dependent calcium channels (VDCC) in both DM-BAPTA-AM-incubated and EGTA-AM-incubated mature mice levator auris neuromuscular junctions (NMJ) was studied. We evaluated the effects of ω-agatoxin IVA (ω-Aga IVA), nitrendipine and ω-conotoxin GVIA (ω-Cg...
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1999
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00316768_v437_n4_p523_Urbano http://hdl.handle.net/20.500.12110/paper_00316768_v437_n4_p523_Urbano |
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paper:paper_00316768_v437_n4_p523_Urbano2023-06-08T14:57:03Z L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals Uchitel, Osvaldo Daniel Calcium channel Cell-permeant calcium buffers DM-BAPTA-AM EGTA-AM Neuromuscular junction calcium calcium channel calcium channel blocking agent animal cell animal experiment animal tissue article calcium current calcium transport electrophysiology male mouse nerve ending nerve potential neuromuscular synapse neurotransmission neurotransmitter release nonhuman priority journal Animals Buffers Calcium Calcium Channel Blockers Calcium Channels Calcium Channels, L-Type Chelating Agents Egtazic Acid Electric Conductivity Evoked Potentials Male Mice Motor Endplate Nitrendipine omega-Agatoxin IVA omega-Conotoxin GVIA Peptides Spider Venoms The involvement of the different types of voltage-dependent calcium channels (VDCC) in both DM-BAPTA-AM-incubated and EGTA-AM-incubated mature mice levator auris neuromuscular junctions (NMJ) was studied. We evaluated the effects of ω-agatoxin IVA (ω-Aga IVA), nitrendipine and ω-conotoxin GVIA (ω-CgTX) (P/Q-, L- and N-type VDCC blockers, respectively) on perineurial calcium currents (ICa) and nerve-evoked transmitter release. The application of ω-Aga IVA (100 nM) drastically reduced perineurial ICa (> 90%) and nerve-evoked transmitter release (> 90% of reduction in quantal content, m) at both DM-BAPTA-AM-incubated and EGTA-AM-incubated NMJ. The L-type VDCC antagonist nitrendipine (10 μM) caused a significant reduction (23 ± 9%, n = 5) of perineurial ICa at DM-BAPTA-AM-incubated NMJ. In addition, after the block of P/Q-type VDCC with ω-Aga IVA (100 nM), nitrendipine reduced (> 90%, n = 2) the remaining perineurial ICa. Such reduction was not observed at EGTA-AM-incubated NMJ, before or after the total block of P/Q-type VDCC. Moreover, nitrendipine did not significantly reduce the quantal content of DM-BAPTA-AM-incubated NMJ. Finally, the application of ω-CgTX (5 μM) did not significantly affect perineurial ICa or nerve-evoked transmitter release at either DM-BAPTA-AM-incubated or EGTA-AM-incubated NMJ. These results show the existence of a nitrendipine-sensitive, L-type component of perineurial ICa in DM-BAPTA-AM-incubated NMJ of mature mice. © Springer-Verlag 1999. Fil:Uchitel, O.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00316768_v437_n4_p523_Urbano http://hdl.handle.net/20.500.12110/paper_00316768_v437_n4_p523_Urbano |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Calcium channel Cell-permeant calcium buffers DM-BAPTA-AM EGTA-AM Neuromuscular junction calcium calcium channel calcium channel blocking agent animal cell animal experiment animal tissue article calcium current calcium transport electrophysiology male mouse nerve ending nerve potential neuromuscular synapse neurotransmission neurotransmitter release nonhuman priority journal Animals Buffers Calcium Calcium Channel Blockers Calcium Channels Calcium Channels, L-Type Chelating Agents Egtazic Acid Electric Conductivity Evoked Potentials Male Mice Motor Endplate Nitrendipine omega-Agatoxin IVA omega-Conotoxin GVIA Peptides Spider Venoms |
| spellingShingle |
Calcium channel Cell-permeant calcium buffers DM-BAPTA-AM EGTA-AM Neuromuscular junction calcium calcium channel calcium channel blocking agent animal cell animal experiment animal tissue article calcium current calcium transport electrophysiology male mouse nerve ending nerve potential neuromuscular synapse neurotransmission neurotransmitter release nonhuman priority journal Animals Buffers Calcium Calcium Channel Blockers Calcium Channels Calcium Channels, L-Type Chelating Agents Egtazic Acid Electric Conductivity Evoked Potentials Male Mice Motor Endplate Nitrendipine omega-Agatoxin IVA omega-Conotoxin GVIA Peptides Spider Venoms Uchitel, Osvaldo Daniel L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals |
| topic_facet |
Calcium channel Cell-permeant calcium buffers DM-BAPTA-AM EGTA-AM Neuromuscular junction calcium calcium channel calcium channel blocking agent animal cell animal experiment animal tissue article calcium current calcium transport electrophysiology male mouse nerve ending nerve potential neuromuscular synapse neurotransmission neurotransmitter release nonhuman priority journal Animals Buffers Calcium Calcium Channel Blockers Calcium Channels Calcium Channels, L-Type Chelating Agents Egtazic Acid Electric Conductivity Evoked Potentials Male Mice Motor Endplate Nitrendipine omega-Agatoxin IVA omega-Conotoxin GVIA Peptides Spider Venoms |
| description |
The involvement of the different types of voltage-dependent calcium channels (VDCC) in both DM-BAPTA-AM-incubated and EGTA-AM-incubated mature mice levator auris neuromuscular junctions (NMJ) was studied. We evaluated the effects of ω-agatoxin IVA (ω-Aga IVA), nitrendipine and ω-conotoxin GVIA (ω-CgTX) (P/Q-, L- and N-type VDCC blockers, respectively) on perineurial calcium currents (ICa) and nerve-evoked transmitter release. The application of ω-Aga IVA (100 nM) drastically reduced perineurial ICa (> 90%) and nerve-evoked transmitter release (> 90% of reduction in quantal content, m) at both DM-BAPTA-AM-incubated and EGTA-AM-incubated NMJ. The L-type VDCC antagonist nitrendipine (10 μM) caused a significant reduction (23 ± 9%, n = 5) of perineurial ICa at DM-BAPTA-AM-incubated NMJ. In addition, after the block of P/Q-type VDCC with ω-Aga IVA (100 nM), nitrendipine reduced (> 90%, n = 2) the remaining perineurial ICa. Such reduction was not observed at EGTA-AM-incubated NMJ, before or after the total block of P/Q-type VDCC. Moreover, nitrendipine did not significantly reduce the quantal content of DM-BAPTA-AM-incubated NMJ. Finally, the application of ω-CgTX (5 μM) did not significantly affect perineurial ICa or nerve-evoked transmitter release at either DM-BAPTA-AM-incubated or EGTA-AM-incubated NMJ. These results show the existence of a nitrendipine-sensitive, L-type component of perineurial ICa in DM-BAPTA-AM-incubated NMJ of mature mice. © Springer-Verlag 1999. |
| author |
Uchitel, Osvaldo Daniel |
| author_facet |
Uchitel, Osvaldo Daniel |
| author_sort |
Uchitel, Osvaldo Daniel |
| title |
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals |
| title_short |
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals |
| title_full |
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals |
| title_fullStr |
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals |
| title_full_unstemmed |
L-type calcium channels unmasked by cell-permeant Ca2+ buffer at mouse motor nerve terminals |
| title_sort |
l-type calcium channels unmasked by cell-permeant ca2+ buffer at mouse motor nerve terminals |
| publishDate |
1999 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00316768_v437_n4_p523_Urbano http://hdl.handle.net/20.500.12110/paper_00316768_v437_n4_p523_Urbano |
| work_keys_str_mv |
AT uchitelosvaldodaniel ltypecalciumchannelsunmaskedbycellpermeantca2bufferatmousemotornerveterminals |
| _version_ |
1768544029890314240 |