Renin-angiotensin-aldosterone Explained

First of all, I will admit freely that this isn't the most "layman-friendly" stuff I've ever posted.  I know we all vary considerably in our desire/willingness to dig into the medical mumbo-jumbo, though, and I thought I would post this for anyone else who wants to put on their waders and get hip-deep in some SERIOUS technical jargon.  :-p

Yes, I watched the whole thing.  And took notes.  Well, I had to keep rewinding several parts over and over again to keep up, and I may have had to look a few things up on other websites to figure out what was going on.  But I made it all the way to the end, and I think I learned a LOT!!  It did put the function of fludrocortisone into perspective, as well as explaining why it would potentially cause low potassium levels.  So, without further ado, I present you with a medical school lecture on the Renin-Angiotensin-Aldosterone System:

http://www.youtube.com/user/DoctorNajeeb#p/c/DEE79BD21254EBD1/0/puM5WCvOBdU


By the way, anyone who does want to try to dig into this, you may need these things that I had to look up because I had trouble understanding what he was saying or deciphering his reading on these ones and I had to figure them out using my Google-Fu.  So you don't have to reinvent the wheel (presumably you'll know it when you get to the parts where you need each term):

Polkissen cells (if you look them up elsewhere online, they are synonymous with Juxtaglomerular cells, I think)
Juxtaglomerular Apparatus (JGA)
GFR=Glomerular Filtration Rate
Zona glomerulosa

(If anyone has questions on it after watching, I can at least attempt to answer them.)

[enzymelover]

Thank you for this. You just took my day's research away from me! My son just had renin and aldosterone levels done two weeks ago (I asked for angiotensin II also, but that one wasn't done).
His renin was normal, as was his sodium and potassium levels, but his aldosterone was very low, so his doc is now thinking of putting him on Florinef. I don't know if this is the best thing to do now, or not. His salt/water balance seems to be good, without salt loading or excessive water consumption, and he does still have the other very low hormones (only cortisol and thyroxine are being replaced right now).

I wanted my son's previous endo to test aldosterone nearly two years ago, when his orthostatic intolerance  began, but he wouldn't do it. He said something about the renin-aldosterone system being separate from the pituitary-adrenal system, and since my son had the pituitary tumor, that's all he wanted to concentrate on. I knew it was a separate system, but still interrelated with adrenal function, and I thought because of the OI it should at least be tested, but until two weeks ago, it never was.

Now I wonder if he's had very low aldosterone for two years. He's going to be admitted for another MRI in 3 weeks so we will definitely be discussing this with his new endo.

[Heiferly]

I'm so happy it was helpful!  I've asked for my renin and aldosterone levels to be tested, but to no avail as well.  I don't know what it will take for me to get someone to test them.  I'm hoping I can find a decent endo at CC.  Where did you find his new endo?  Is this one that he's seeing now pretty good?

I tested positive for hypocortisolemia but I hit a brick wall with it and have dropped the issue.  I can't help but wonder if I would do better if I were on something for the cortisol.  Has it helped him?  What is given for the cortisol replacement?  (I know it's a different situation with the pituitary tumor, but to be honest, I don't even know WHAT is causing mine.  The endo refused to even *consider* the idea that anything pituitary could be wrong, let alone look for anything along those lines.  Okay, I'll stop blabbing on about my endo issues again, sorry.)

Do you have the article that talks about renin and aldosterone levels in POTS?  It's from a Vandy study ... I can dig it up for you if you don't have it.  

[enzymelover]

I hope you can find a good endo at CC. Do you mean to say you've never had a doctor test your pituitary function, the whole time you've been sick? That's outrageous! You should have had a full endocrine workup to at least rule out any endocrine causes that may be contributing to your illness.
Insist that your pituitary function be tested - TSH, GH, LH, ACTH, and ADH. Whatever endo you find, look him in the eye and insist.

My son's endo works closely with the neurosurgeon who did his surgery, at UCSF. So far, I would say he's very good, although he admits the dysautonomia symptoms are beyond anything he's dealt with in his practice. He's trying though. He had some training at Vanderbilt. Dr. Robertson there was his professor. He suggested trying to get my son into Vandy for testing, but we're looking for help closer to home right now.

If you are not maintaining sufficient cortisol levels, I think you should ask for a trial of hydrocortisone, or dexamethasone to see if it helps you. My son's dex put an end to his problem with nausea, the hydrocortisone didn't help really, with most of his symptoms.
He still has severe OI and heat intolerance, and other symptoms of AD, but overall, his energy and strength are better (as long as he's not trying to stand up!) A DYNAMIC cortisol response is needed to help with all illnesses, and the lack of a DYNAMIC hormone response may be partly to blame for his severe OI. (In other words, hormone levels don't rise as they should with stresses such as digestion, emotion, exercise, and of course sickness). Heck, just standing up is too much stress on his system!

I don't have that article from the Vandy study. Don't go to any trouble to find it, only if you happen to come across it.

Thanks again.

[Heiferly]

No trouble at all!  One good turn deserves another!  You're helping me a ton with the information you are giving me ... the endo stuff is the aspect that my case really hasn't been handled on yet, so I *really* appreciate it!

Here's the article:

http://circ.ahajournals.org/cgi/content/full/111/13/1574