CONTACT: JENNIFER CRONIN
2130 Medical Laboratories
Iowa City IA 52242
(319) 335-9917; fax (319) 335-8034
Release: Sept. 23, 1999
Researchers examine new way to possibly induce vascular
IOWA CITY, Iowa By lowering an individual's
heart rate, doctors someday may be able to trigger the sprouting of new blood
vessels without having to resort to invasive methods, according to results
from a University of Iowa Health Care study.
In recent years, a substance known as vascular endothelial
growth factor (VEGF) has attracted the attention of researchers who are looking
for ways to develop new blood vessels to replace those either damaged or blocked
due to coronary conditions.
Until now, the focus has been on using either injections
of the needed VEGF or the gene therapy strategy, which involves delivering
the VEGF to its intended destination via a disabled cold virus carrier. Robert
J. Tomanek, Ph.D., UI professor of anatomy and cell biology, and his research
team are looking at a less intrusive, more natural approach.
"Gene therapy is one avenue to bring about vascular
growth, but if you can use either pharmacological interventions or some interventions
that change the physiology of the heart so that the heart does it naturally,
then I think that is better because it is noninvasive," Tomanek said.
Wei Zheng, Ph.D., a postdoctoral fellow in Tomanek's
lab, was able to get laboratory rats to produce the needed VEGF by using a
heart rate lowering drug. A lowered rate allows the heart to fill with more
blood between each beat. The increased blood causes the heart to stretch,
which Tomanek believes induces the animal to produce VEGF.
VEGF then triggers endothelial cells, the building
blocks of the blood vessels, to proliferate.
"VEGF causes the endothelial cells to migrate, line up
and actually form the vascular structures," Tomanek explained.
Tomanek and his colleagues are continuing to study
VEGF and other growth factors, attempting to learn more about the mechanisms
involved with coronary vascular growth.
"Hopefully, this can get to the stage where it can
be applied to humans," Tomanek said.
A grant from the National Institutes of Health supplied
funding for the study, which recently appeared in the journal Circulation
Research. Other scientists who contributed to the study are
Margaret D. Brown, Ph.D., a lecturer at the University
of Birmingham; Tommy Brock, Ph.D., director of pharmacology at Texas Biotechnology
Corp.; and Robert J. Bjercke, Ph.D., senior scientist at Texas Biotechnology
University of Iowa Health Care describes the partnership
between the UI College of Medicine and the UI Hospitals and Clinics and the
patient care, medical education and research programs and services they provide.