Toxic effects of silver-silver chloride electrodes on vascular smooth muscle.

We found that silver, either as silver metal or silver chloride, exerted toxic effects on the smooth muscle of isolated cannulated hamster cheek pouch arterioles. Silver initially stimulated the smooth muscle, producing a marked vasoconstriction. The vessels then dilated back to control diameters. Once the arterioles began to dilate, they became refractory to norepinephrine or potassium stimulation. We caution the use of silver in the presence of smooth muscle, especially when tissue mass is small or free protein concentration is low.