Physio Q - cytp450

[ArchivalUser]

In cortisol deficiency, each of the following is deficient EXCEPT: A. Catecholamine induced glycogenolysis, B. Catecholamine induced lipolysis C. Catecholamine induced Vasoconstriction D. Pituitary secretion of ACTH E. the rate at which a decrease in plasma osmolality is corrected

ans is D

Options A,B,C, E are correct, but option D is wrong one.

pls explain why option E is correct.

[ArchivalUser]

pls explain about this q pls

[ArchivalUser]

As far as i know decreased cortisol will inversily affect ADH..so with a decrease in cortisol there is an increase in ADH. Therefore if more water is retained then there will be less solute withmore solution so the osmolality will decrease and therefore a delay in correction would be seen... ANY OTHER OPINIONS

[ArchivalUser]

Thank u dear xahdum16x

[ArchivalUser]

Is there any relation of cortisol with ADH ? I do not know that

I feel this way .... cortisol has some salt and water retention activities ... so decreased cortisol ...... decreased salt and water retention ..... so decreased rate of correction when plasma osmolarity is low .......

[ArchivalUser]

Just a little more information....
this is from up-to-date
The hypersecretion of ADH seen in cortisol deficiency may be in part due to the reductions in systemic blood pressure and cardiac output induced (via an unknown mechanism) by the lack of cortisol. However, a more important mechanism may be that ADH is an ACTH secretagogue, the secretion of which is stimulated by corticotropin releasing hormone (CRH) from the paraventricular nuclei in the hypothalamus [5-8]. Cortisol feeds back negatively on CRH and therefore ADH, an inhibitory effect that is removed with adrenal insufficiency [5,9]. It is unclear if the action of cortisol on ADH release is direct or is mediated by changes in the secretion of CRH [7].

http://www.uptodate.com/patients/content...4xX/BDnDMf