<chemical> (oc-6-22)-pentakis(cyano-c)nitrosoferrate(2-). A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins. ... Pharmacological action: antihypertensive agents, indicators and reagents, sulfhydryl reagents, vasodilator agents. ... ... Found on http://www.encyclo.co.uk/local/20973