Involvement of Na,K-pump in SEPYLRFamide-mediated reduction of cholinosensitivity in Helix neurons
Involvement of Na,K-pump in SEPYLRFamide-mediated reduction of cholinosensitivity in Helix neurons
SEPYLRFamide acts as an inhibitory modulator of acetylcholine (ACh) receptors in Helix lucorum neurones. Ouabain, a specific inhibitor of Na,K-pump, (0.1 mM, bath application) decreased the ACh-induced inward current (ACh-current) and increased the leak current. Ouabain decreased the modulatory SEPYLRFamide effect on the ACh-current. There was a correlation between the effects of ouabain on the amplitude of the ACh-current and on the modulatory peptide effect. Ouabain and SEPYLRFamide inhibited the activity of Helix aspersa brain Na,K-ATPase. Activation of Na,K-pump by intracellular injection of 3 M Na acetate or 3 M NaCl reduced the modulatory peptide effect on the ACh-current. An inhibitor of Na/Ca-exchange, benzamil (25 muM, bath application), and an inhibitor of Ca(2+)-pump in the endoplasmic reticulum, thapsigargin (TG, applied intracellularly), both prevented the effect of ouabain on SEPYLRFamide-mediated modulatory effect. Another inhibitor of Ca(2+)-pump in the endoplasmic reticulum, cyclopiazonic acid (applied intracellularly), did not prevent the effect of ouabain on SEPYLRFamide-mediated modulatory effect. These results indicate that Na,K-pump is responsible for the SEPYLRFamide-mediated inhibition of ACh receptors in Helix neurons. Na/Ca-exchange and intracellular Ca(2+) released from internal pools containing TG-sensitive Ca(2+)-pump are involved in the Na,K-pump pathway for the SEPYLRFamide-mediated inhibition of ACh receptors.
sepylrfamide, na, k-pump, acetylcholine receptors, released ca2+, na/ca-exchange, helix neurons
103-112
Pivovarov, Arkady S.
efd8efe9-0ce8-42bf-8e51-9660620d0c74
Foreman, Richard C.
5e7796fe-6411-4495-aa90-5f17d5d67ffa
Walker, Robert J.
9368ac2d-f1e9-4bd9-a4b4-4a161c4aa140
February 2007
Pivovarov, Arkady S.
efd8efe9-0ce8-42bf-8e51-9660620d0c74
Foreman, Richard C.
5e7796fe-6411-4495-aa90-5f17d5d67ffa
Walker, Robert J.
9368ac2d-f1e9-4bd9-a4b4-4a161c4aa140
Pivovarov, Arkady S., Foreman, Richard C. and Walker, Robert J.
(2007)
Involvement of Na,K-pump in SEPYLRFamide-mediated reduction of cholinosensitivity in Helix neurons.
Regulatory Peptides, 138 (2-3), .
(doi:10.1016/j.regpep.2006.08.009).
(PMID:17049630)
Abstract
SEPYLRFamide acts as an inhibitory modulator of acetylcholine (ACh) receptors in Helix lucorum neurones. Ouabain, a specific inhibitor of Na,K-pump, (0.1 mM, bath application) decreased the ACh-induced inward current (ACh-current) and increased the leak current. Ouabain decreased the modulatory SEPYLRFamide effect on the ACh-current. There was a correlation between the effects of ouabain on the amplitude of the ACh-current and on the modulatory peptide effect. Ouabain and SEPYLRFamide inhibited the activity of Helix aspersa brain Na,K-ATPase. Activation of Na,K-pump by intracellular injection of 3 M Na acetate or 3 M NaCl reduced the modulatory peptide effect on the ACh-current. An inhibitor of Na/Ca-exchange, benzamil (25 muM, bath application), and an inhibitor of Ca(2+)-pump in the endoplasmic reticulum, thapsigargin (TG, applied intracellularly), both prevented the effect of ouabain on SEPYLRFamide-mediated modulatory effect. Another inhibitor of Ca(2+)-pump in the endoplasmic reticulum, cyclopiazonic acid (applied intracellularly), did not prevent the effect of ouabain on SEPYLRFamide-mediated modulatory effect. These results indicate that Na,K-pump is responsible for the SEPYLRFamide-mediated inhibition of ACh receptors in Helix neurons. Na/Ca-exchange and intracellular Ca(2+) released from internal pools containing TG-sensitive Ca(2+)-pump are involved in the Na,K-pump pathway for the SEPYLRFamide-mediated inhibition of ACh receptors.
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e-pub ahead of print date: October 2006
Published date: February 2007
Keywords:
sepylrfamide, na, k-pump, acetylcholine receptors, released ca2+, na/ca-exchange, helix neurons
Organisations:
Centre for Biological Sciences
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Local EPrints ID: 372567
URI: http://eprints.soton.ac.uk/id/eprint/372567
ISSN: 0167-0115
PURE UUID: fa34efa2-f737-4033-8689-54e517c8f74e
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Date deposited: 09 Dec 2014 10:45
Last modified: 15 Mar 2024 04:03
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Author:
Arkady S. Pivovarov
Author:
Richard C. Foreman
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