what will plasma ADH change after mannitol use?

[match2011]

400mM mannitol infusion

what will the plasma ADH and osmolality change?

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[warriordoc911]

mannitol is diuretic that causes high tubular osmolarity thus preventing water from being reabsorbed from the lumen. basically keeps the water in the lumen leading to excessive volume loss. So if you excrete excess volume then that would mean increased plasma osmolarity which triggers the release of ADH. it's the same as hypovolemia. This was in NBME 6 and i selected: 1. increase plasma osm
2. increase ADH

Btw i had the extended form and i got this question right and used the same reasoning as i gave you.

Note: Mannitol can only be filtered but not reabsorbed/secreted thus creating high osmolarity in the tubular lumen.

400mM mannitol infusion

what will the plasma ADH and osmolality change?

 

[match2011]

Thanks

 

[engineeredout]

Someone correct me if I'm wrong, but won't osmolality actuallydecrease initially due to the osmotic pull of water into the vasculature when it is first given iv?

 

[am9451]

Someone correct me if I'm wrong, but won't osmolality actuallydecrease initially due to the osmotic pull of water into the vasculature when it is first given iv?

Used the same reasoning on NBME 6 today and got the question wrong. Sigh.

 

[engineeredout]

Used the same reasoning on NBME 6 today and got the question wrong. Sigh.

Depends on the wording though right? The immediate effect would be decreased osmolality, but soon afterwards it would be increased