title: Interaction between stannous chloride and calcium channel blockers in frog neuromuscular transmission.
abstract: We have investigated the interactions between stannous chloride (SnCl2) and calcium (Ca) channel blockers on endplate potentials (e.p.p.) and on miniature endplate potentials (m.e.p.p.) to determine which type of channel (among L-, N-, and T-type) participates in the SnCl2-induced increase in Ca entry into motor nerve terminals. The e.p.p. amplitude augmented by 30 microM SnCl2 was decreased by cumulative addition of 10 microM CdCl2 or 0.5 microM omega-conotoxin but not by 10 microM NiCl2 or 5 microM nicardipine. The SnCl2 (30 microM)-induced rise in m.e.p.p. frequency in high-potassium medium was reduced by 0.5 microM omega-conotoxin but not by 5 microM nicardipine. These results suggest that activation of the N-type Ca channel is involved in the SnCl2-induced increase in Ca entry into the nerve terminals.
authors.affiliation: Department of Dental Pharmacology, Matsumoto Dental College, Shiojiri, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hattori
authors.forename: H
authors.initials: H
authors.lastname: Maehashi
mesh_terms: D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D019256:Cadmium Chloride; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D009529:Nicardipine / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D011892:Rana catesbeiana; D014001:Tin / Q000494:pharmacology*; D017971:Tin Compounds; D020960:omega-Conotoxins
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010456:Peptides, Cyclic; D017971:Tin Compounds; D020960:omega-Conotoxins; D002104:Cadmium; C053423:Conus magus toxin; C023599:stannous chloride; D014001:Tin; D009529:Nicardipine; D019256:Cadmium Chloride; D002118:Calcium