Another substance that helps control arterial pressure is the hormone angiotensin (ANG II). Then, there’s an enzyme that converts angiotensin (ACE and ACE2). A recent study found that exercise normalized levels of these enzymes in rabbits with chronic heart failure. The conclusion, though many unknowns are still involved, is that exercise can re-balance such enzymes in the part of the brain that controls autonomic functioning.
Nobody’s making any promises that this will convert to a change for humans with chronic heart failure. But there do seem to be some chemical similarities between the human and the rabbit brain. I had a pet rabbit for 8 years. I’m glad she wasn’t one that got used for the research, but I trust that today’s experiments are by law conducted humanely on all living creatures.