hyperaldosteronism and metabolic alkalosis

[westernmed007]

Quick Question:
With hyperaldosteronism in the kidney you increase the number of NA/K pumps, thus wouldn't your K+ concentration in the cell be very high, thus inhibiting K+ being reabsorbed in the distal tubule and thus inhibiting the secretion of H+ (which would cause acidosis)? Why then does hyperaldosteronism cause alkalosis?

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[flumazenil]

quick reply, apologize if this is incorrect- top of my head explanation. ...when aldosterone is secreted, sodium becomes reabsorbed in in the distal tubule, which creates a negative charge on the luminal side. As a result, H+ is attracted to this positive charge and leaves the principal cells. Any hydrogen lost in the distal tubule equates to a HCO3- REABSORBED into the basal side of the principal cell ( blood). Since there is an increase in HCO3- in the plasma, H+ goes out of cells and K+ goes into cells to compensate for the metabolic alkalosis

 

[anesthesiarocks]

Quick Question:
With hyperaldosteronism in the kidney you increase the number of NA/K pumps, thus wouldn't your K+ concentration in the cell be very high, thus inhibiting K+ being reabsorbed in the distal tubule and thus inhibiting the secretion of H+ (which would cause acidosis)? Why then does hyperaldosteronism cause alkalosis?

I think you're thinking way too much about it. I always just think of it as this: aldosterone causes reabsorption of Na and secretion of K+ and H+, so if you have too much aldosterone, you'll secrete too much H+, lose too much acid, and have an alkalosis state.

Is this an oversimplified(and possible incorrect) way of looking at it? Perhaps. But if you look at the tubule as the incredibly complex thing it is and try to overanalyze every little thing, you'll end up being confused on questions where a more direct simplistic approach could answer the question right in 10 seconds.

 

[Taus]

I think you're thinking way too much about it. I always just think of it as this: aldosterone causes reabsorption of Na and secretion of K+ and H+, so if you have too much aldosterone, you'll secrete too much H+, lose too much acid, and have an alkalosis state.

Is this an oversimplified(and possible incorrect) way of looking at it? Perhaps. But if you look at the tubule as the incredibly complex thing it is and try to overanalyze every little thing, you'll end up being confused on questions where a more direct simplistic approach could answer the question right in 10 seconds.

agree w/ that 100%....leave that thinking to the nephrologists....increase aldost = take back Na and piss out K and H+.....simple as that

 

[blue2015]

I was thinking through this and this came up. I thought that I'd post an explanation that explains why.

1. Primary hyperaldosteronism --> K secretion in the CD --> K loss

2. State of K+ depletion: HYPOKALEMIA

3. Increased activity of the H/K+ ATPase (Type B intercalated cells in CD); shift of H+ ions into cells (as there's low K+)

4. H+ secretion --> H+ loss

5. Metabolic alkalosis

 

[Tenn!s]

I was thinking through this and this came up. I thought that I'd post an explanation that explains why.

1. Primary hyperaldosteronism --> K secretion in the CD --> K loss

2. State of K+ depletion: HYPOKALEMIA

3. Increased activity of the H/K+ ATPase (Type B intercalated cells in CD); shift of H+ ions into cells (as there's low K+)

4. H+ secretion --> H+ loss

5. Metabolic alkalosis

Can you tell me where your pic form ?
i want the ref. for my report ^^
THX

 

[medstud97]

Quick Question:
With hyperaldosteronism in the kidney you increase the number of NA/K pumps, thus wouldn't your K+ concentration in the cell be very high, thus inhibiting K+ being reabsorbed in the distal tubule and thus inhibiting the secretion of H+ (which would cause acidosis)? Why then does hyperaldosteronism cause alkalosis?

High potassium concentration inside the cell will cause secretion in the distal tubule not reabsorption.
Primary hyperaldosteronism will cause increased secretion of potassium-> hypokalemia -> with decreased potassium concentration in tubular fluid , the positive charge of potassium opposing hydrogen will decrease resulting in increased hydrogen secretion.