John S. Floras

Canada Research Chair in Integrative Cardiovascular Biology

Tier 1 - 2017-11-01
Renewed: 2012-03-01
University of Toronto
Canadian Institutes of Health Research


Research involves

Identifying and modifying mechanisms responsible for the initiation and progression of cardiac and vascular disease.

Research relevance

New insights into normal and abnormal circulatory regulation will lead to the development of novel approaches to counter or prevent cardiovascular disease.

The Cardiovascular Intranet

The heart is not "an island, unto itself." Rather, it is a richly innervated muscle, whose timing and performance is exquisitely regulated by a sympathetic nervous accelerator and by a parasympathetic brake. It is also a sensory organ and a hormone factory, whose products affect changes in blood pressure and salt and water excretion. Similarly, blood vessels are not passive conduits or reservoirs. They constrict and dilate in response to instruction from the brain and circulating hormones, and from their own internal communicators. Together, heart and blood vessels make up the cardiovascular "intranet."

In health, these overlapping systems work silently and efficiently to allow our bodies to adjust to the daily demands of our environment. When these internal controls break down, debilitating symptoms, organ damage, and premature death result.

Canada Research Chair Dr. John Floras hopes to develop and test the impact of new treatments on common and debilitating conditions as diverse as heart failure, high blood pressure, and kidney failure. His work focuses on the heart and blood vessels.

Dr. Floras was the first in this country to study the cardiovascular intranet directly in conscious humans, by recording from sympathetic nervous impulses that were generated by the brain and directed at blood vessels, causing them to constrict and raise blood pressure.

He later used imaging methods to quantify the pumping action of the heart and the dilation and contraction of major arteries, and mathematical tools to discriminate between the accelerator and braking function of these nerves on the heart's pacemaker. In addition, he carried out calculations of organ exposure to the nerves' transmitters and took measurements of circulating hormones that regulate heart function and blood vessel tone.

Dr. Floras's methods have been employed, in productive collaborations, to dismantle traditional barriers to interdisciplinary patient-oriented research and to uncover the mechanisms involved in cardiovascular disease. His approach to integrative cardiovascular biology is unique within Canada.