title: Reversed effect of caffeine on non-contractile and contractile Ca2+ mobilization operated by acetylcholine receptor in mouse diaphragm muscle.
abstract: Caffeine effects on contractile and acetylcholine receptor-related non-contractile Ca2+ mobilization were investigated in phrenic nerve-diaphragm muscles of mice with neostigmine. Caffeine enhanced at 0.25-5 mM, and decreased at 7-20 mM the total amount of contractile Ca(2+)-aequorin luminescence (Ca2+ transients), but only decreased at 2-10 mM non-contractile Ca2+ transients. Pretreatment with formamide (2 M for 30 min) abolished contractile Ca2+ transients, but did not affect non-contractile ones. These results suggest that non-contractile Ca2+ mobilization is not due to direct Ca2+ release from sarcoplasmic reticulum, but due to direct modulation by nicotinic acetylcholine receptor.
authors.affiliation: Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Kondoh
authors.forename: H
authors.initials: H
authors.lastname: Tsuneki
authors.forename: M
authors.initials: M
authors.lastname: Kimura
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D003964:Diaphragm / Q000378:metabolism; D005559:Formamides / Q000494:pharmacology; D008297:Male; D051379:Mice; D009119:Muscle Contraction; D009132:Muscles / Q000378:metabolism*; D009388:Neostigmine / Q000494:pharmacology; D011950:Receptors, Cholinergic / Q000502:physiology*; D012433:Ryanodine / Q000494:pharmacology
chemical_list: D005559:Formamides; D011950:Receptors, Cholinergic; D012433:Ryanodine; D009388:Neostigmine; D002110:Caffeine; C031066:formamide; D002118:Calcium