title: Effects of cupric ions on isolated guinea-pig ileum.
abstract: The possible biological significance of low concentrations of Cu2+ on the guinea-pig ileum has been investigated. Responses to nerve stimulation by single electrical shocks, acetylcholine (ACh), and histamine and the response to ACh of depolarized muscle were examined. In summary, Cu2+ has diverse and dose-dependent effects on the ileum. A stimulant effect dominates in intestine accommodated in physiological saline solution. The excitatory effect of the ion, in the concentration range 10 nM-1 microM, is probably due to stimulation of a depolarization-coupled initiation of the contraction. The inhibitory effect of Cu2+ (10 nm-1 microM) is presumably due to a decreased Ca2+ availability for the contractile process. In a higher concentration range (10 microM-100 microM) the stimulant action could also, in part, be related to a copper-induced release of Ca2+ from a storage site. No effect that certainly could be ascribed to a neuronal site of action could be observed. The possible effect of Cu2+, released during corrosion of dental alloys, on oral excitable tissue such as taste and pain receptors is discussed.
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects; D003035:Cobalt / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology*; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects* / Q000294:innervation; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009532:Nickel / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
chemical_list: D009599:Nitroprusside; D003035:Cobalt; C022838:nickel chloride; D003300:Copper; D009532:Nickel; D014700:Verapamil; C018021:cobaltous chloride