Research Awards Recipients

Lay Summary
The vascular system brings blood to the tissues, where nutrients are exchanged for wastes, and returns blood to the heart. We talk about the arterial “tree” because of structural similarities to actual trees. A single trunk, the aorta, leaves the heart and progressively gives off major arteries (branches) to supply organs such as brain, liver, kidneys, etc. Within each organ the artery branches progressively into smaller and smaller arteries, eventually arriving at about 1 billion capillaries, the tiny vessels where exchange of nutrients and waste occurs. Blood pressure generated by the heart pushes blood flow and blood flow is controlled by the smallest arteries, just upstream from the capillaries. These arteries are muscular and contract (just like closing a tap) when blood pressure increases. Like a real tree, there is random variation in the structure of arterial branches, and this translates into varied blood flow in each branch. Every organ faces what can be called the “3 bears”problem – how to deliver, not too much, not too little, but “just right” blood flow to all capillaries.
 
High blood pressure (hypertension) causes damage to the tiny capillaries. The kidney is protected against hypertension by stabilization of the blood flows when blood pressure rises (it "autoregulates" its blood flow). Previous work showed that this autoregulation is a network process so that all the branches receive "just right" blood flow. But, just like the plumbing in a house, not all the pipes are the same length and some mechanism is needed to make sure that all the taps get the same flow at the same pressure. That means that the different branches must talk to each other. This communication occurs via transmission of electrical signals that instruct cells in the artery walls to contract. These types of signals are unique to the kidney and the underlying mechanism is unknown. Previous studies demonstrated the importance of this electrical communication pathway by showing that blocking it impairs autoregulation and "just right" flow in the whole kidney.
 
Dr. Planes’s project objective is to investigate the basis for this kidney-specific electrical signalling pathway that is crucial to controlling blood flow in the kidney and protecting it from changes in blood pressure. She will use a genetically modified rat that lacks a specific protein, connexin40. This breaks the communication pathway along the vessels. Using this model, she expects to show in more detail how the kidney blood flow is regulated and how kidney damage occurs when it fails.