Effect of calcium and calmodulin antagonists on contractile responses of the human uterine artery

Abstract

0.7 and 10pUM. 4 Calmodulin antagonists, particularly trifluoperazine and flunarizine, caused a greater inhibition of the NA than of the K response. 5 These results indicate that besides the extracellular calcium which appears to be the major source of activator calcium, there is an intracellular pool of calcium which can be utilized to activate, albeit to a limited extent, drug-induced contractile responses.

Diverse actions of cadmium on the smooth muscle myosin phosphorylation system

“…The mechanism of Cd action on smooth muscles is as yet poorly understood. Since smooth muscles exhibit a high degree of sensitivity to agents which inhibit Ca influx [2,3] and cadmium is a Ca channel blocker in cardiac cells [4], it may be expected that Cd influences smooth muscle activity via a similar route. However, current data indicate that the in vitro effects of Cd on smooth muscle tissues are highly concentration-dependent.…”