Low concentrations of inorganic mercury inhibit in vitro autonomic transmission in the presence of albumin.
The influence of albumin, 4.5 and 45 g/l, on the effects of Hg2+, 10(-9)-10(-3) M, on the neuromuscular transmission of the isolated guinea-pig ileum and vas deferens was investigated. Hg2+, 10(-9)-10(-6) M, transiently increased the basal tone of the ileum in Tyrode solution without albumin. Albumin, 4.5 g/l, reversed this stimulant effect but enhanced the contractile response to direct muscle stimulation. This contractile response also increased in the vas deferens. Albumin, 45 g/l, obliterated the stimulant effects of Hg2+ on the smooth muscle of the ileum but not of the vas deferens. The effects caused by higher concentrations of Hg2+, 10(-5)-10(-4) M, were only partly inhibited when albumin was present. When neurogenic contractions were elicited in the presence of albumin (45 g/l), Hg2+, 10(-9)-10(-4) M, reduced the contractions in both organs. Consequently, Hg2+ in concentrations presently considered acceptable in blood plasma (10(-9)-10(-8) M) suppressed both cholinergic and adrenergic neuromuscular transmission even in the presence of albumin.
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; D001341:Autonomic Nervous System / Q000187:drug effects*; D018680:Cholinergic Antagonists; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D008297:Male; D008628:Mercury / Q000037:antagonists & inhibitors* / Q000494:pharmacology; 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; D008628:Mercury