dopamine.
Posted on 07/19/2011 12:34:34 PM PDT by decimon
The neurotransmitter dopamine is best known for its roles in the brain – in signaling pathways that control movement, motivation, reward, learning and memory.
Now, Vanderbilt University Medical Center investigators have demonstrated that dopamine produced outside the brain – in the kidneys – is important for renal function, blood pressure regulation and life span. Their studies, published in the July Journal of Clinical Investigation, suggest that the kidney-specific dopamine system may be a therapeutic target for treating hypertension and kidney diseases such as diabetic nephropathy.
Previous studies had suggested a role for dopamine in regulating kidney function and total body fluid volume, "but how that mechanism works was not clear," said Raymond Harris, M.D., chief of the Division of Nephrology and Hypertension at Vanderbilt.
To explore dopamine's role in the kidney, Harris and Ming-Zhi Zhang, M.D., assistant professor of Medicine at Vanderbilt, eliminated kidney-specific dopamine production in mice (by knocking out a dopamine-generating enzyme only in the kidney) and studied the outcome.
They found that mice lacking kidney dopamine had high blood pressure at baseline and became more hypertensive when they consumed a high-salt diet, suggesting they may be a good model of salt-sensitive (essential) hypertension, Harris said. Alterations in the kidney dopamine system may predispose individuals to hypertension, he noted.
The investigators also showed that elimination of kidney dopamine increased renin production, which activates the angiotensin II system to increase salt and water reabsorption – and produce hypertension.
"These animals retain salt and water when they don't have sufficient dopamine production in the kidney," Harris said. "Our studies highlight this whole other hormonal system that appears to balance or put the brakes on the renin-angiotensin system."
Currently, the renin-angiotensin system is the major target for treating chronic kidney diseases. Discovering another target – the kidney dopamine system – is exciting, the researchers said. They are exploring whether specific drugs that enhance the kidney dopamine system are effective in blocking hypertension and treating progressive kidney diseases.
The investigators predicted changes in kidney function in the mouse model, but they were "very surprised" to discover that the modified mice only lived about half as long as normal mice (15 months versus 30 months). They found increases in stress-related proteins in the kidney, heart and vasculature, suggesting that elimination of kidney dopamine causes systemic effects, Harris said.
"This kidney-specific dopamine system is not only important for kidney function and blood pressure regulation, but also for the overall health of the animal," Harris said. "If the dopamine system in the kidney is altered, the animals have a markedly shortened life span."
###
The research was supported by the National Institutes of Health, the Vanderbilt O'Brien Center and by the Veterans Administration. Harris is the Ann and Roscoe R. Robinson Professor of Nephrology.
Ping
This is interesting news. Having both Hypertension and adult onset diabetes, I like hearing this.
dopamine.
This natural product help with blood pressure and aging.
I’ve been taking it for three months and can really tell a difference.
http://www.mylifevantage.com/radio/default.aspx
save
Ping.
Now it would be good to know if there's anything people can do to improve their kidney dopamine level.
Intrarenal dopamine deficiency leads to hypertension and decreased longevity in mice.
Since they alluded to the renin/angiotensin system, you might want to know something about blood pressure meds for diabetics and what blood pressure meds increase the risk of type 2 diabetes.
Choice of antihypertensive drug in the diabetic patient.
New-onset diabetes and antihypertensive treatment
FReepmail me if you want on or off the diabetes ping list.
Can’t remember if I posted this or not. I have OBS (old brain syndrome)
http://diabetes.webmd.com/news/20110302/aggressive-diabetes-threapy-may-raise-death-risk
There is a real danger in trying to achieve “ideal” numbers in diabetics, especially as they get older. No 65-year-old is going to have the same blood pressure and glucose numbers as a 25-year-old. Trying to reach that goal may cause more harm than good. So, yes, treat the hypertension, but don’t go overboard. The body has a way of compensating for whatever we do to it. :-)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.