Watts, a professor of pharmacology and toxicology, has focused her research on whether serotonin (5-HT) plays a role in hypertension. The story of her research is interesting not only because it is important to find a treatment for this serious illness, but because her research resembles a mystery novel, in which the detective has her eye set on a likely suspect, only to find out that the bad guy may be the good guy.
Watts hypothesized that since it takes less serotonin to make hypertensive blood vessels contract, that hypertensive individuals may have a higher number of receptors. This could explain why the blood vessels of hypertensive individuals react more strongly to serotonin. She experimented with one receptor and found that blocking it reduced blood pressure.
In 2006, Watts gave serotonin to both hypertensive and normal rats, reasoning that serotonin would raise blood pressure in the non-hypertensive rats and that the rats with hypertension would experience an even greater rise in blood pressure. Instead, the serotonin reduced blood pressure by 15 to 20 percent in the non-hypertensive rats and by 33 percent in the hypertensive animals. Watts’ lab has repeated the experiment with the same results.
These results have Watts wondering if serotonin levels rise because serotonin is trying to reduce blood pressure. “I’m wondering if hypertensive people have higher level of 5-HT because that’s a good thing,” Dr. Watts said. “Now we’re trying to figure out the multiple ways 5-HT can play with the cardiovascular system to cause these results.”
One possibility is that once an individual suffers hypertension, it changes how the blood vessel works, toughening vessels to handle the higher pressure and changing how it reacts in the presence of serotonin. “It’s really hard to tell which is the cause and which is the effect,” Watts said.
MEDICA.de; Source: American Physiological Society