New research in rats explores the role of perivascular adipose tissue (PVAT) the fat that builds around arteries in maintaining vascular health
Islamabad (Pakistan Point News / Online - 27th February, 2020) New research in rats explores the role of perivascular adipose tissue (PVAT) the fat that builds around arteries in maintaining vascular health. The findings may have implications for conditions such as hypertension and atherosclerosis.New research suggests that scientists should add a fourth layer to the structure of a functional blood vessel.Stephanie Watts, a professor of pharmacology and toxicology at the College of Osteopathic Medicine at Michigan State University in East Lansing, is the first and corresponding author of the study.
Prof. Watts and team explain in their paper that PVAT secretes substances that help relax the arteries, noting that this is a known fact in the medical community.They hypothesized that in addition to producing these vasoactive substances, there was another way in which PVAT may be good for the arteries.PVAT improves stress relaxationThe scientists examined thoracic aorta rings from Sprague Dawley rats with and without PVAT, recording how the tissue stress relaxed over 30 minutes.
"The presence of PVAT increased the amount of stress relaxation," write the authors. In fact, "[a] PVAT ring separated from the aorta demonstrated more profound stress relaxation than did the aortic ring itself.""In our study, PVAT reduced the tension that blood vessels experience when stretched. And that's a good thing because the vessel then expends less energy. It's not under as much stress."In addition to looking at the thoracic aorta which brown fat envelops the researchers also tested the superior mesenteric artery, which has white fat surrounding it.
Tests in both arteries produced the same result: There was more stress relaxation in the presence of PVAT than there was in its absence."So, this tells us, it's not just a one-off," says Prof. Watts. "It's not something you see only in this particular vessel or this particular species or this particular strain. But that maybe it's a general phenomenon."Redefining �functional blood vessels'The researchers think that the findings should help redefine the role of PVAT, as well as the structure of blood vessels.
Until now, they explain, experts believed that PVAT only served to store fat and that the standard structure of blood vessels comprised three parts: an innermost layer, a middle layer, and an outermost layer.The researchers think that the medical community should consider PVAT to be the fourth structural layer of a blood vessel."For years, we ignored this layer in the lab, it was thrown out; in the clinic, it wasn't imaged. But now we're discovering it may be integral to our blood vessels," Prof. Watts says.
