Rhodnius prolixus - a blood sucking bug from Hemiptera order confined to drier savannah areas from southern Mexico to northern South America. This insect by transmitting the parasite Trypanosoma cruzi is a principal vector of Chagas' disease, the incurable illness damaging the heart and nervous system and afflicting millions of people in Middle and South America.
Rhodnius prolixus is capable of ingesting 300 mg of blood in 15 min. Such high efficiency blood intake is made possible by a special mouthpart this bug has developed along with a sophisticated mechanism of avoiding host hemostatic reaction (blood coagulation, platelet aggregation and vasoconstriction).
Rhodnius prolixus contains in its salivary glands several pharmacologically active compounds that, when injected with its saliva into the host skin, counteract the host's hemostatic reaction, and permit the bug to minimize its probing and feeding times. Four closely related proteins found in Rhodnius saliva are responsible for its vasodilator, anticoagulant and antiplatelet aggregation activity. Because they have been found to bind nitric oxide in their native state, and act as a storage and delivery system for nitric oxide, they have been named nitrophorins.