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I know I'm missing something obvious, hoping someone can point it out. I'm now doing a systems review!

Currently on the Endocrine section, and can't seem to figure this out. On one hand, Cortisol is secreted during times of severe stress (eg. Infection). But Cortisol is a Glucocorticoid, which are known to SUPPRESS the immune system. So how does Cortisol help fight infections, when the immune system is suppressed?

Thanks!
 

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Cortisols natural function is to prepare body for stress by mobilizing fat and supplying glucose to body
So far i have never heard that body can use it for immune modulation (except for its artificial uses)
 
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Cortisol is one of the four stress hormones (the others being GH, Glucagon and Epi). By definition, a stress hormone is released to make sure that your body has enough sugar to fight off the stressor (infection, injury etc). The way cortisol mediates its immunosuppressive effect is through leukocytosis. In order to understand this effect, you must know that in the human body at any given point in time, there are two populations of leukocytes: A circulating population (which you measure in your blood) and a marginating population (which hangs out in tissues). I believe the percentage of circulating/marginating cells is about 50/50 in a healthy individual. But if that individual gets infected with a microbe, his or her circulating pool tends to decrease becuase now more cells are needed at the site of infection. The way these cells make it from the bloodstream to the tissue is through adhesion molecules known as Integrins. Cortisol tends to inhibit the expression of these molecules by leukocytes so that they're not able to move from the blood to the infected tissue. This means that a person taking cortisol is going to have an INCREASED number of leukocytes in their plasma.
 

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my question- cortisol-insulin

if cortisol inhibits insulin's effect, and insulin induces glucose movement into the cell ,then how cortisol helps in fulfilling energy demand by glucose, wouldn't glucose just satay in blood stream, and not in the cell where its needed.:confused:
 

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I know it is probably late but I thought of posting an explanation in case anyone was searching for this. One of the main purposes of cortisol is to provide enough glucose for brain neurons in times of stress. These neurons have glucose transporters that are not affected by insuline levels which means that their gluose uotake is not dependent on insuline. This is why even though cortisol decreases glucose uptake in most tissues it actually helps to provide more glucose to the brain.
 
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