It produces NO

Nov 6, 2007 09:11 GMT  ·  By
All those vessels and corpus cavernosum must fill with blood during the erection. NO is in charge with this
   All those vessels and corpus cavernosum must fill with blood during the erection. NO is in charge with this

We know that hemoglobin, the iron-rich pigment of the blood's red cells is the carrier of the oxygen from lungs to tissues and carbon dioxide from tissues to lungs. Now, a team from Wake Forest University, the National Institute of Health and other institutions has found, in a research published online on Nov. 4 in the journal Nature Chemical Biology, that hemoglobin acts as a catalyst in turning nitrite salt to the vasodilator nitric oxide.

The hemoglobin activated nitric oxide was found to control blood flow and, surprisingly, the oxidized hemoglobin type, previously linked just to diseased states, was found to be the most effective.

"We believe we have solved the paradox of how hemoglobin mediates the conversion of nitrite to nitric oxide in a way that it is not immediately destroyed in the red cell and so it can be effective biologically," said senior author Daniel Kim-Shapiro, professor of physics at Wake Forest.

In the bloodstream, hemoglobin eliminates free nitric oxide produced by the blood vessels, that's why nobody imagined hemoglobin was involved in the synthesis of nitric oxide. But a 2003 research made by the same team found that nitrite salt, employed to cure meat and previously regarded as biologically inactive, was used by cells for storing nitric oxide.

That discovery boosted the investigation of nitrite as a possible cure for many illnesses like sickle cell disease, myocardial infarction, pulmonary hypertension, stroke and atherosclerosis.

The new research found that the nitrite-hemoglobin interaction produces dinitrogen trioxide (N2O3), subsequently split into nitric oxide (NO) and nitrogen dioxide (NO2).

The trick was that the intermediate molecule, nitrite-methemoglobin, could not be detected by electron paramagnetic resonance spectroscopy, the most advanced current analysis technique and the reaction was unveiled only through indirect measurement.

"Using a variety of biophysical techniques and by careful examination of the rates of reactions and the products that are made when experimenting with hemoglobin and nitrite, we were able to discover this reaction mechanism," said Kim-Shapiro.

Perhaps you do not know, but NO is essential in inducing an erection, as it dilates the blood vessels for filling the penis with blood. After ejaculation, its levels in the penile vessels drop and so does the erection.