After isolating the stem cells, they were injected into
the corpus cavernosum area of the penis.
It turns out that creating and sustaining them depends on a delicate balance between relaxation and contraction of blood vessels in the penis's
corpus cavernosum, a spongelike tissue.
PDE5 stops the blood from entering
the corpus cavernosum, the tubular formations in the penis that inflate with blood to cause an erection.
By inhibiting the actions of PDE5, blood can flood
the corpus cavernosum and cause the penis to become erect.
Sildenafil affects cyclic guanosine monophosphate (cGMP), which is found in areas such as
the corpus cavernosum and pulmonary vasculature.