Blocking Nitric Oxide May Prevent Vascular Spasm

A study in mice has found that inhibiting the production of nitric oxide can reduce coronary artery spasm, which is an under-recognized and under-treated source of damage to heart muscle that can lead to reduced cardiac function and death. The findings were published in the March 1, 2004, issue of the Journal of Clinical Investigation.

The research team previously found that damaged heart cells produce more of an enzyme that helps synthesize nitric oxide, and that high concentrations were present in regions of damaged heart tissue. In the current study, they show that the inhibition of nitric oxide can reduce, but not eliminate, coronary artery spasm. The discovery suggests new ways to prevent vasospasm in patients at risk. Drugs that block nitric oxide production are already being tested. Newer calcium channel blockers that target smooth muscle cells but do not interfere with cardiac muscle may also have a role.

"”Even though many cardiologists ignore it, spasm happens,” said study director Elizabeth McNally, M.D., Ph.D., associate professor of medicine and genetics at the University of Chicago (IL, USA). "We found one factor, but we suspect that other factors also play a role.”