Understanding the Role of Potassium in Blood Pressure Regulation

[isyang94]

How does potassium affect the blood pressure? how does it lower the blood pressure with the help of the kidney(collecting duct)?
thanks

 

[SW VandeCarr]

How does potassium affect the blood pressure? how does it lower the blood pressure with the help of the kidney(collecting duct)?
thanks

There are studies that show potassium supplements can lower blood pressure. The effect is relatively small, but consistent.

http://jama.ama-assn.org/content/277/20/1624.short

The hormone aldosterone controls potassium secretion and sodium resorption in the kidney. Potassium is not reabsorbed so its loss is proportional to urine formation. Aldosterone is very sensitive to low blood levels of potassium and will cause active renal resorption of sodium in response to maintain electrolyte (anion and cation) balance. Among other things, sodium retention leads to fluid retention which leads to higher blood pressures. Potassium supplements, or preferably a diet high in potassium rich foods, can help maintain normal potassium levels and thus reduce the activity of aldosterone in causing the retention of sodium.

 

[Evo]

Do not ever self medicate with potassium unless you see your doctor first. If your potassium levels are low, then your doctor can prescribe a potassium supplement, and will do occasional blood tests to monitor your levels. Potassium overdose is potentially lethal, it is the lethal part of the injection given to people sentenced to death.

 

[SW VandeCarr]

Do not ever self medicate with potassium unless you see your doctor first. If your potassium levels are low, then your doctor can prescribe a potassium supplement, and will do occasional blood tests to monitor your levels. Potassium overdose is potentially lethal, it is the lethal part of the injection given to people sentenced to death.

As with any over the counter drug or supplement, doses well above the recommended range can be toxic, including aspirin and acetaminophen (Tylenol (R)). In fact, a systemically toxic dose of oral KCl is difficult to achieve in healthy human subjects with normal renal function because doses many times those recommended induce nausea and vomiting. The same cannot be said for aspirin, acetaminophen or supplements containing vitamin A for example.

Having said that, I don't believe supplemental KCl (which is also used in a pure form as a salt substitute) is a good way to obtain potassium. There are plenty of good foods that are high in potassium including avocados, bananas, white beans and raisins.

http://www.inchem.org/documents/sids/sids/KCHLORIDE.pdf

 

[Evo]

Potassium overdose is very serious as a relatively small amount can stop your heart. This has nothing to do with your original post, just a warning about potassium intake.

Can salt substitute kill you?

Dear Cecil:

There is a common (I hesitate to say "popular") salt substitute called NoSalt that consists of the compound potassium chloride (which is indeed a salt, but not a sodium-based one). This compound is used in other salt substitutes as well. Curiously, this very same compound has been used on several occasions by Dr. Jack Kevorkian for euthanasia (including, if I am not mistaken, his most recent, televised one) and also in executions. It works by stopping the heart.

continued...

http://www.macrobiotic.org/SaltSubDanger.htm

https://www.physicsforums.com/showpost.php?p=2143376&postcount=24

You can get potassium supplements in both a pill and a liquid form by prescription (it's given by prescription because you really can overdose if you take too much)

 

[Proton Soup]

for a dietary approach, consider the DASH diets http://en.wikipedia.org/wiki/DASH_diet

it won't kill you to eat a vegetable, i promise ;)

 

[SW VandeCarr]

Potassium overdose is very serious as a relatively small amount can stop your heart. This has nothing to do with your original post, just a warning about potassium intake.

There's a huge difference between oral KCl and KCl given intravenously. IV KCl is rapidly lethal. The LD50 for oral KCl is 3020mg/kg body weight (see the link in my previous post). For a 70kg person, that's 211,400mg (211 grams or nearly a half a pound). It's unlikely that anyone could ingest that much in a short time and not vomit. Oral KCl is rapidly excreted and does not accumulate in people with normal renal function.

http://www.macrobiotic.org/SaltSubDanger.htm

Does this link meet the standard for PF? Jack Kevorkian killed his patients with IV KCl. If he used NoSalt, he did it by dissolving the salt in water and giving it IV .
.

https://www.physicsforums.com/showpost.php?p=2143376&postcount=24

Moonbear is talking about the experiences of his mother with hypokalemia (low potassium). Yes, this is a dangerous condition and can occur with a potassium poor diet, especially when combined with drinking a lot of coffee, tea or taking other substances that promote diuresis. Liquid KCl for oral consumption afaik is dispensed only with a prescription and is not available OTC. In any case, I would expect the LD50 to be in a similar range as for any form of oral KCl.

 

[Evo]

There's a huge difference between oral KCl and KCl given intravenously. IV KCl is rapidly lethal. The LD50 for oral KCl is 3020mg/kg body weight (see the link in my previous post). For a 70kg person, that's 211,400mg (211 grams or nearly a half a pound). It's unlikely that anyone could ingest that much in a short time and not vomit. Oral KCl is rapidly excreted and does not accumulate in people with normal renal function.

Orally, KCl is toxic in excess; the LD50 is around 2500 mg/kg (meaning that a lethal dose for 50% of people weighing 75 kg (165 lb) is about 190 g (6.7 ounces), or about 38 teaspoons).

http://wiki.answers.com/Q/Lethal_dose_of_potassium_chloride

The lethal amount is less for women and thinner people. If you have problems that cause you to retain potassium, it's even more of an issue. People need to have their potassium levels checked by a doctor and only take a supplement if a doctor considers it necessary. We get an ample supply of potassium just from the foods we eat.

I am on potassium supplements since in the ER they found that my potassium level was a 1, out of a range of 1-4, I was immediately put on a potassium IV, and have to have my blood tested periodically.

 

[Evo]

Good information on potassium. In other words, do not self medicate, see a doctor.

http://www.umm.edu/altmed/articles/potassium-000320.htm

 

[Borek]

Orally, KCl is toxic in excess; the LD50 is around 2500 mg/kg

To quote first googled MSDS on NaCl:

Acute oral toxicity (LD50): 3000 mg/kg [Rat.]

So the difference is rather negligible, in both cases you need to eat several ounces to be at risk.

 

[Proton Soup]

here, try this: http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/new_dash.pdf

diet low in sodium, high in K, Mg, Ca.

 

[nismaratwork]

On the other hand, Nu-Salt in water = lethal injection... oh well.

 

[SW VandeCarr]

On the other hand, Nu-Salt in water = lethal injection... oh well.

Did you mean NoSalt (crystalline KCl)? Do you know why it's about as safe orally as NaCl (with normal renal function and serum K levels), but highly lethal IV?

 

[nismaratwork]

Did you mean NoSalt (crystalline KCl)? Do you know why it's about as safe orally as NaCl (with normal renal function and serum K levels), but highly lethal IV?

Ahhh, NoSalt...

... and yeah, that's why I said lethal INJECTION, not lethal seasoning. :tongue:

Still, scares the living hell out of older folks on a diet, in Florida... when I'm bored.

 

[jackal5671]

Orally, KCl is toxic in excess; the LD50 is around 2500 mg/kg (meaning that a lethal dose for 50% of people weighing 75 kg (165 lb) is about 190 g (6.7 ounces), or about 38 teaspoons).

http://wiki.answers.com/Q/Lethal_dose_of_potassium_chloride

The lethal amount is less for women and thinner people. If you have problems that cause you to retain potassium, it's even more of an issue. People need to have their potassium levels checked by a doctor and only take a supplement if a doctor considers it necessary. We get an ample supply of potassium just from the foods we eat.

I am on potassium supplements since in the ER they found that my potassium level was a 1, out of a range of 1-4, I was immediately put on a potassium IV, and have to have my blood tested periodically.

I've had high blood pressure and this is what I always do. Thanks for the post!

 

[docwithabox]

Wow, a potassium of 1 is VERY low. Are you sure it wasn't 3.1 or 2.1? If that is the true level, you really should be strict about staying under the care of a physician who can help you manage this. I have seen people die with levels higher than that.

The main point of this thread is: don't take potassium supplements without speaking to a doctor first.

 

[Evo]

Wow, a potassium of 1 is VERY low. Are you sure it wasn't 3.1 or 2.1? If that is the true level, you really should be strict about staying under the care of a physician who can help you manage this. I have seen people die with levels higher than that.

The main point of this thread is: don't take potassium supplements without speaking to a doctor first.

The emergency room doc said it was a 1 and was freaked out and immediately started me on a potassium IV. He seemed to think I should be dead. That's not even why I was in the ER. My left leg had swollen so badly so quickly that I couldn't move it. I was there for testing for a blood clot. They found nothing.

I just got the results of last week's test and I'm a 4, so the supplements seem to be working.