Tadaflo buys online 35% off in PayPal. When sexual stimulation causes the local release of nitric oxide in the corpus cavernosum, nitric oxide activates the enzyme guanylyl cyclase, which increases levels of cGMP. The increased cGMP levels in the corpus cavernosum produce smooth muscle relaxation and inflow of blood into the penile tissues, thereby producing an erection. PDE5 degrades...