Cyclopiazonic acid is a sarcoplasmic reticulum Ca(2+)-pump inhibitor of rat aortic muscle.

The effects of a mycotoxin, cyclopiazonic acid (CPA), on the contractile function of rat aortic smooth muscle rings were investigated to test the hypothesis that CPA selectively inhibits the sarcoplasmic reticulum Ca(2+)-pump. This hypothesis was tested by two types of experimental approaches. First, we compared the ability of the vascular muscle rings to relax upon washout of the agonists following the contraction induced by high concentration …