After 60 years, scientists find the missing link in our body's blood pressure control

https://medicalxpress.com ^ | AUGUST 3, 2021 | by Josh Barney, University of Virginia

[Red Badger]

Credit: Pixabay/CC0 Public Domain

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University of Virginia School of Medicine researchers have determined the location of natural blood-pressure barometers inside our bodies that have eluded scientists for more than 60 years.

These cellular sensors detect subtle changes in blood pressure and adjust hormone levels to keep it in check. Scientists have long suspected that these barometers, or "baroreceptors," existed in specialized kidney cells called renin cells, but no one has been able to locate the baroreceptors until now.

The new findings, from UVA Health's Dr. Maria Luisa S. Sequeira-Lopez and colleagues, finally reveal where the barometers are located, how they work and how they help prevent high blood pressure (hypertension) or low blood pressure (hypotension). The researchers hope the insights will lead to new treatments for high 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," said Sequeira-Lopez, of UVA's Department of Pediatrics and UVA's Child Health Research Center. "So the renin cells are sensors and responders."

Sensing blood pressure

The existence of a pressure sensor inside renin cells was first proposed back in 1957. It made sense: The cells had to know when to release renin, a hormone that helps regulate blood pressure. But even though scientists suspected this cellular barometer had to exist, they couldn't tell what it was and whether it was located in renin cells or surrounding cells.

Sequeira-Lopez and her team took new approaches to solving this decades-old mystery. Using a combination of innovative lab models, they determined that the baroreceptor was a "mechanotransducer" inside renin cells. This mechanotransducer detects pressure changes outside the cell, then transmits these mechanical signals to the cell nucleus, like how the cochlea in our ear turns sound vibrations into nerve impulses our brain can understand.

The researchers have unlocked exactly how the baroreceptors work. They found that applying pressure to renin cells in lab dishes triggered changes within the cells and decreased activity of the renin gene, Ren1. The scientists also compared differences in gene activity in kidneys exposed to lower pressure and those exposed to higher pressure.

Ultimately, when the baroreceptors detect too much pressure outside the renin cell, production of renin is restricted, while blood pressure that is too low prompts the production of more renin. This marvelous mechanism is vital to the body's ability to maintain the correct blood pressure. And now, after more than 60 years, we finally understand how and why.

"I feel really excited about this discovery, a real tour de force several years in the making. We had a great collaboration with Dr. [Douglas] DeSimone from the Department of Cell Biology," Sequeira-Lopez said. "I am also excited with the work to come, to unravel the signaling and controlling mechanisms of this mechanotransducer and how we can use the information to develop therapies for hypertension."

Explore further

Could aggressive blood pressure treatments lead to kidney damage?

More information: Hirofumi Watanabe et al, Renin Cell Baroreceptor, a Nuclear Mechanotransducer Central for Homeostasis, Circulation Research (2021).

DOI: 10.1161/CIRCRESAHA.120.318711

Journal information: Circulation Research

Provided by University of Virginia

[Wuli]

Now they next need to identify if long term issues of how well the kidneys-to-bladder functions are working, or not working so well, has an impact on the renin cells in the kidneys and thus indirectly on blood pressure. I think that is important to finding some of the “first-cause” ways (likely more than one) by which high blood pressure is instigated. Without that sort of question and findings about it, I think many blood pressure related issues remain a “which comes first, the chicken or the egg” kind of question.

How this relates to long time blood pressure remedies is not so far a stretch, given one of the early and easiest remedies has been very simple diuretics that reduce the water in the system and by doing so has some blood pressure lowering affect. It opens the question of why would there be such a remedy needed (and working) if the kidney to bladder functions were always working at their best in the first place? You’d think a water retention issue would originate NOT in the blood pressure it has an affect on, but what is causing the water retention in the first place, and thus attacking the root cause(s) would be better long term aid to blood pressure than diuretic pills.

[logi_cal869]

Nitrogen is your friend. Check it out. Most tire shops maintain pressure for free when required, one-time cost.

[Scrambler Bob]

make a tire pressure reporting system that doesn’t trigger the warning light for no reason.
= = =

VW uses the anti-lock braking system. It monitors wheel speed, and if a tire is ‘faster’, the radius is decreasing, indicating air loss.

No sender inside the tire.

Mine sent a signal. Tires looked OK. Three were 34, one was 26 and it looked fine. Had a nail.

[chrisinoc]

Good article, thanks for posting. I suffer from both high and low blood pressure that my kidney specialist is treating now. She’s taken me off a lot of blood pressure medication that wasn’t helping me that long term and hurting my kidney function.

I’m going to print the article and show it to my regular and kidney doctors.

[Scrambler Bob]

If you check ‘cold’ in the am you are off to a good start.

Driving will heat the tires and increase pressure. That is OK.

One person kept checking his tires and letting out air as they got hot and pressure went up. And then they would flex and get hot and pressure go up, and he would let air out repeatedly. Finally blew a tire. Might have been a loaded pick up situation.

If I set my tires ‘cold’ at say 32 degF and traveled where it was a lot hotter I would adjust. Again in the am, setting to spec. pressure.

Now if I went from snowy to desert hell fire in one day, I might want adjust mid day.

[Scrambler Bob]

Air is about 80% nitrogen.

So you have a head start on nitrogen in your tires.

It is my theory that the oxygen permeates out of the tire faster than the nitrogen. So you fill with air, and ooze out the oxygen.

Bye and Bye your nitrogen percentage goes up and the addition of air is not needed so often.

[logi_cal869]

https://jalopnik.com/heres-the-deal-with-nitrogen-filled-tires-1795659391

[Red Badger]

Hopefully this discovery will lead to a ‘universal’ med that works for everyone, every time.

Over the years I have been on several different meds. Each worked for a year or two then they stop working and the doc has to find another type..............................

[Red Badger]