Development of a method for measuring activity of the human sympathetic nervous system. This knowledge supported the introduction of beta blockers as an effective therapy for heart failure and may pave the way for a device treatment of resistant hypertension.
Before 1980, there was no reliable way to measure how the sympathetic nervous system — the body's "fight or flight" system — was communicating with internal organs. Without that information, understanding and treating conditions like heart failure and hypertension was hampered by significant gaps in knowledge.
Baker Institute researchers changed that. Their Human Neurotransmitters laboratory developed the isotope dilution method: a technique for measuring the release of noradrenaline, the sympathetic nerve transmitter, from specific organs including the heart and kidneys. The technique became the gold standard in the field, adopted in studies ranging from clinical trials to experiments on board Space Shuttle Columbia.
What they discovered challenged a long-held assumption. Rather than the sympathetic nervous system responding as a single, uniform system — uniformly "on" or "off" — the research showed that individual organs can have quite different levels of sympathetic activity at the same time. This was a significant departure from the prevailing theory.
Building on this, Baker Institute scientists were the first to demonstrate that the degree of increased cardiac sympathetic tone was a key predictor of how quickly heart failure would progress and whether a patient would survive. This knowledge supported the introduction of beta blockers as an effective therapy for heart failure. It also underpins current research into catheter-based renal nerve ablation — a device-based treatment for patients with resistant hypertension.
