Blood pressure "barometer" cells discovered in the kidney
Researchers at the University of Virginia School of Medicine have discovered a population of natural barometers that monitor and maintain our blood pressure. The cellular sensors have long been presumed to be located in a certain type of cell in the kidney, but have only now been detected after decades of searching.
Both high and low blood pressure can be problematic, so to keep it in the goldilocks zone the body has “baroreceptors” that sense blood pressure. The main ones are located in the carotid sinus in the neck, where they can monitor blood pressure in this major artery and quickly instruct the brain to adjust the pressure as needed by way of the heart and blood vessels. Others are located in the aortic arch, right next to the heart.
But in 1957 it was predicted that another group of these baroreceptors should be present in the kidneys, specifically in what are called renin cells. These cells release the enzyme renin, which helps to regulate blood pressure, so it was presumed that they should have some way to sense blood pressure in order to react to it. More than 60 years of searching, however, have failed to turn up any trace.
The team investigated the mystery in renin cells grown in lab culture. They found that this baroreceptor works as a mechanotransducer – essentially, it detects pressure changes outside the cell, then sends signals to the nucleus to respond.
When they applied pressure to the renin cells, the baroreceptor reacted by decreasing activity in the renin gene Ren1, which in turn reduces the amount of renin released and thus reduces blood pressure. When the pressure is low, on the other hand, the gene can express more renin to raise blood pressure.
“It was exhilarating to find that the elusive pressure-sensing mechanism, the baroreceptor, was intrinsic to the renin cell, which has the ability to sense and react, both within the same cell,” says Maria Luisa Sequeira-Lopez, lead author of the study. “So the renin cells are sensors and responders.”
The team says that the new discovery could potentially pave the way towards new treatments for high blood pressure.
The research was published in the journal Circulation Research.
Source: UVA Health