Kidney Diuretics

[MDwannabe7]

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Okay, so tell me if I understand this correctly. The descending loop is permeable to water and therefore by the bottom of the loop, the filtrate is pretty concentrated. The ascending loop is permeable to salt and therefore by the time the filtrate reaches the distal convoluted tubule, it is fairly dilute. In the presence of ADH, the collecting duct is permeable to water and therefore loses it, resulting in the production of a small amount of concentrated urine. In the absence of ADH, the collecting duct is not permeable to water, resulting in the production of a large amount of dilute urine. In the presence of a diuretic, such as caffeine, sodium reabsorption is inhibited, which results in water also being retained in the filtrate. This ends in the production of a large amount of concentrated urine?

 

[AZFutureDoc]

Diuretics do just what their name says, and simply do the opposite of ANTIdiuretic hormone. Since ADH makes low volume, high concentration urine, the opposite, high volune, low concentration urine, will be produced. It sounds like your getting mixed up where aldosterone comes into play.

 

[MDwannabe7]

Diuretics do just what their name says, and simply do the opposite of ANTIdiuretic hormone. Since ADH makes low volume, high concentration urine, the opposite, high volune, low concentration urine, will be produced. It sounds like your getting mixed up where aldosterone comes into play.

Well, I read that diurectics inhibit the reabsorption of sodium, which consequently inhibits further reabsorption of water. I was thinking that all that sodium in the urine would cause it to be concentrated, but when you also have all that water, it makes it dilute. However, in reference to aldosterone - which to my understanding stimulates the reabsorption of sodium and the secretion of potassium from the collecting duct - can I therefore conclude, that diuretics affect both ADH and aldosterone? Therefore, the effect of a diuretic would be to inhibit ADH secretion, making the collecting duct impermeable to water AND to inhibit aldosterone secretion, thereby inhibiting the reabsorption of sodium and the secretion of potassium?

 

[hants]

in terms of concentration/volume, if you know what sodium does, you know water does. water always follows sodium, sodium follows water. this may help in some shape or form, if it isnt, o well

 

[AZFutureDoc]

That's a good question actually. I'm not sure what a diuretic does to aldosterone. What I do know is that caffeine and alcohol inhibit ADH, causing their effects through direct inhibition of only ADH. I think it is safe to say that aldosterone isn't much of a player when looking at the effects of a diuretic. The key difference between the two is that ADH makes s small volume of high concentrated urine. And Aldosterone makes a small volume of nonconcentrated urine.