Pentobarbital sodium inhibits calcium uptake in vascular smooth muscle

Abstract

This report demonstrates that the commonly used anesthetic agent, pentobarbital sodium, in concentrations of 1 · 10 −4 to 2 · 10 −3 M inhibits calcium (Ca 2+) uptake in both rat aortic and portal venous smooth muscle. The data indicate that total exchangeable Ca 2+ in portal vein is reduced by about 15% in 1 · 10 −4 M pentobarbital sodium, while the intracellular exchangeable Ca 2+ is reduced by 24%. On the other hand, in aortic smooth muscle, while 5–20 · 10 −4 M pentobarbital sodium reduces total exchangeable Ca 2+ by about 15%, intracellular Ca 2+ is reduced by 22% in 5 · 10 −4 M pentobarbital sodium and by 38% in 2 · 10 −3 M pentobarbital sodium. The present studies thus reveal that concentrations of pentobarbital sodium known to be present during induction of surgical anesthesia can exert significant inhibitory effects on exchangeability and transmembrane movement of Ca 2+ in at least two different types of blood vessels.