Albumin inhibits effects of Cu2+ on autonomic postganglionic transmission of guinea-pig ileum and vas deferens.
The influence of albumin, 4.5 and 45 g/l, on the effects of Cu2+, 10(-9)-10(-3) M, on the neuromuscular transmission of the isolated guinea-pig ileum and vas deferens was investigated. Low concentrations of Cu2+, 10(-9)-10(-6) M, caused a slight and transient increase of the contractile response to direct muscle stimulation of the vas deferens. Albumin at 4.5 g/l inhibited this effect. The basal tone of the ileum increased transiently when Cu2+ was added in the presence of albumin, 4.5 g/l. A stimulant action of Cu2+, 10(-9)-10(-6) M, was seen on both organs, when contractions were induced by nerve stimulation. All these effects were inhibited by albumin, 45 g/l. Higher concentrations of Cu2+, 10(-5)-10(-4) M, increased the basal tone of the ileum and the vas deferens. In the presence of albumin, 45 g/l, this stimulating effect of Cu2+ appeared in higher concentrations. The results suggest that Cu2+ is more likely to influence the function of neuronal tissues when the concentration of protein is low.
Moberg
L E
LE
Department of Prosthodontics, Karolinska Institutet, Stockholm, Sweden.
Appelgren
B
B
Sjöstrand
N O
NO
D018674:Adrenergic Antagonists; D000418:Albumins / Q000494:pharmacology*; D000818:Animals; D001338:Autonomic Fibers, Postganglionic / Q000187:drug effects*; D018680:Cholinergic Antagonists; D003300:Copper / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects*; D009466:Neuromuscular Blocking Agents; D014649:Vas Deferens / Q000187:drug effects
D018674:Adrenergic Antagonists; D000418:Albumins; D018680:Cholinergic Antagonists; D009466:Neuromuscular Blocking Agents; D003300:Copper