The September 2020 highlighted “VTPP Science in Action” article (link included above and below) comes from the laboratory of Dr. Cris Heaps. The manuscript outlines a series of elegant experiments that report for the first time an unexpected positive effect of exercise training on small arteries isolated from an ischemic area of the heart. The vessels display a surprisingly enhanced contractile behavior that challenge the idea that only increased dilation promotes increased blood flow into the ischemic myocardium. The data support the idea that parallel upregulation of paradoxical signaling mechanisms likely function to optimize the control of coronary tone. The signaling pathways were elegantly identified using microvessel myographs and whole-cell voltage patch clamp techniques. The involvement of the various pathways (intracellular free Ca2+, Ca2+/calmodulin-dependent protein kinase II, Rho-kinase, PKC) was performed using a sensitive series of selective pharmacologic inhibitors. Figure to the right summarizes the pathways and inhibitory pathways studied in the Heaps article. It is the integration of these disparate signaling pathways that maintain blood flow appropriately to meet the metabolic needs of the collateral-dependent myocardial region as well as aid in the maintenance of coronary flow. Congratulations again to all the members of the Heaps team for the highly impactful and potentially paradigm shifting work. There is still much to be done!
https://journals.physiology.org/doi/pdf/10.1152/ajpheart.00384.2020