Monoclonal antibody to beta 2 subunit of neuronal nicotinic receptor depresses the postjunctional non-contractile Ca2+ mobilization in the mouse diaphragm muscle.
The involvement of subtypes of nicotinic acetylcholine receptor (nAChR) in the postjunctional non-contractile Ca2+ mobilization was investigated in mouse diaphragm muscles treated with an anticholinesterase, using monoclonal antibodies (mAbs) to nAChR subunits. mAb 210 (specific for alpha 1 subunit of muscle nAChR) depressed contractile Ca2+ transients without affecting non-contractile Ca2+ transients. mAb 270 (specific for beta 2 subunit of neuronal nAChR) depressed only non-contractile Ca2+ transients. mAb 210 did not completely block the ACh-activated channel currents in flexor digitorum brevis muscle cells. The present findings indicate that the anti-beta 2 mAb 270-related subtype of nAChR may postsynaptically operate the non-contractile Ca2+ mobilization at the neuromuscular junction, suggesting the involvement of a subtype different from the usual muscle-type nAChR.
Kimura
I
I
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
Tsuneki
H
H
Dezaki
K
K
Nojima
H
H
Kimura
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D003964:Diaphragm / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009121:Muscle Denervation; D018733:Nicotinic Antagonists; D017434:Protein Structure, Tertiary; D011978:Receptors, Nicotinic / Q000737:chemistry / Q000276:immunology
D000911:Antibodies, Monoclonal; D018733:Nicotinic Antagonists; D011978:Receptors, Nicotinic; D002118:Calcium