MCG researchers have shown part of that complexity may be the smooth muscle cells in the internal pudendal arteries of females communicate, agreeing to contract and relax, while male smooth muscle cells make independent decisions to just relax.
They found one other distinction: females were more sensitive to Viagra, or sildenafil, while males were most sensitive to Levitra, or vardenafil.
Previous studies on the effectiveness of these drugs focused on the cavernosal tissue, or penis. The internal pudendal artery actually feeds the penile artery which is buried deep in the penis where numerous caverns enable it to be flaccid when not engorged with blood. Physical stimulation of the area causes the tissue, endothelial cells and nerves to release nitric oxide, a powerful dilator of blood vessels. The system works pretty much the same way in the vagina and clitoris.
"If you have too much constriction or not enough relaxation to allow blood to go through the internal pudendal artery, you are not going to get the net effect of an erection," Dr. Allahdadi says. "That is why we wanted to begin to characterize what was going on in this blood vessel."
Perhaps as importantly, the MCG scientists and others are beginning to believe sexual dysfunction provides an early, or at least visible, clue of vascular disease. Vascular problems, that can result from diabetes, hypertension, high cholesterol and the like, are a major cause of sexual dysfunction in men and women. "You don't feel atherosclerosis but you know darn well if you are not getting an erection," Dr. Webb says. In fact, the MCG scientists are beginning to look at animal models of disease states, such as diabetes, to see what it does to these internal pudendal arteries.
|Contact: Toni Baker|
Medical College of Georgia