Control of the circulation?

Nitroprusside directly relaxes arterial and venous smooth muscle, acting as a vasodilator. You do the rest! Here is a site to get you started: a href="http://cpharm.vetmed.vt.edu/VM8784/CARDIOVASCULAR/vasodilators.htm" rel="nofollow"http://cpharm.vetmed.vt.edu/VM8784/CARDI…/a