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    Why does glucocorticoid hormone enter cells via a transport protein in the plasma membrane? Aren't steroids lipid-soluble, hence able to diffuse through the phospholipid bilayer directly?

    Also if they are secreted by endocrine glands into the bloodstream, how do they travel to the target cell, because I thought steroids were not water-soluble?

    I got the information from:

    https://www.youtube.com/watch?v=Y3a4...AMve45&index=7

    Thanks!
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    Moved to the biology section of the website. They may have an answer for you
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    (Original post by champion1)
    Why does glucocorticoid hormone enter cells via a transport protein in the plasma membrane? Aren't steroids lipid-soluble, hence able to diffuse through the phospholipid bilayer directly?

    Also if they are secreted by endocrine glands into the bloodstream, how do they travel to the target cell, because I thought steroids were not water-soluble?

    I got the information from:

    https://www.youtube.com/watch?v=Y3a4...AMve45&index=7

    Thanks!
    As you mentioned, glucocorticoid hormones are steroid hormones, and are therefore lipid-soluble. That being said, glucocorticoid hormones enter the cell through protein transporters in the plasma membrane for more efficient transport than diffusion; the cell can also exert a degree of control over the glucocorticoid hormone entrance using plasma transporters than simple passive diffusion.

    Since glucocorticoid hormones are fat-soluble, they are released from endocrine glands directly into the bloodstream and are transported bound to specific carrier proteins, called corticosteroid-binding globulin (aka. Transcortin). The production of Transcortin occurs in the liver and is increased in response to oestrogens.

    Take a look at this 'Action of Glucocorticoid Hormone' animation, I found it really useful:

    http://highered.mheducation.com/site...d_hormone.html
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    (Original post by loukas2993)
    As you mentioned, glucocorticoid hormones are steroid hormones, and are therefore lipid-soluble. That being said, glucocorticoid hormones enter the cell through protein transporters in the plasma membrane for more efficient transport than diffusion; the cell can also exert a degree of control over the glucocorticoid hormone entrance using plasma transporters than simple passive diffusion.

    Since glucocorticoid hormones are fat-soluble, they are released from endocrine glands directly into the bloodstream and are transported bound to specific carrier proteins, called corticosteroid-binding globulin (aka. Transcortin). The production of Transcortin occurs in the liver and is increased in response to oestrogens.

    Take a look at this 'Action of Glucocorticoid Hormone' animation, I found it really useful:

    http://highered.mheducation.com/site...d_hormone.html
    Thank you! This is really helpful. Btw the animation from your link is the same one as the animation in my link, but thanks ayway - the animation is really useful.
 
 
 
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