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← Can steroids save your life? - Anees Bahji

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Mostrar Revisión2 creada 06/16/2020 por lauren mcalpine .

  1. Steroids: they’re infamous
    for their use in sports.
  2. But they’re also found in inhalers,
    creams to treat poison ivy and eczema,
  3. and shots to ease inflammation.
  4. The steroids in these medicines aren’t
    the same as the ones used to build muscle.
  5. In fact, they’re all based on
    yet another steroid—
  6. one our body produces naturally,
    and we can’t live without.
  7. Taking a step back, the reason
    there are so many different steroids

  8. is because the term refers to substances
    with a shared molecular structure,
  9. rather than shared effects on the body.
  10. Steroids can be naturally occurring
    or synthetic,
  11. but what all steroids have in common
    is a molecular structure
  12. that consists of a base of four rings
    made of 17 carbon atoms
  13. arranged in three hexagons
    and one pentagon.
  14. A molecule must contain
    this exact arrangement to be a steroid,
  15. though most also have side chains—
  16. additional atoms that can dramatically
    impact the molecule’s function.
  17. Steroids get their name
    from the fatty molecule cholesterol.
  18. In fact, our bodies make steroids
    out of cholesterol.
  19. That fatty cholesterol base
    means that steroids

  20. are able to cross fatty cell membranes
    and enter cells.
  21. Within the cell, they can directly
    influence gene expression
  22. and protein synthesis.
  23. This is different from many other types
    of signaling molecules,
  24. which can’t cross the cell membrane
  25. and have to create their effects
    from outside the cell,
  26. through more complicated pathways.
  27. So steroids can create their effects
    faster than those other molecules.
  28. Back to the steroids
    in anti-inflammatory medications:

  29. all of these are based on a naturally
    occurring steroid called cortisol.
  30. Cortisol is the body’s
    primary stress signal,
  31. and it has a huge range of functions.
  32. When we experience a stressor—
  33. anything from a fight with a friend,
    to spotting a bear,
  34. to an infection or low blood sugar—
  35. the brain reacts by sending a signal from
    the hypothalamus to the pituitary gland.
  36. The pituitary gland then sends a signal
    to the adrenal glands.
  37. The adrenal glands produce cortisol,
    and release some constantly.
  38. But when they receive the signal
    from the pituitary gland,
  39. they release a burst of cortisol,
  40. which spurs the body to generate
    more glucose for energy,
  41. decrease functions not immediately
    related to survival, like digestion,
  42. and can activate
    a fight-flight-or-freeze response.
  43. This is helpful in the short term,
    but can cause undesirable side effects
  44. like insomnia and lowered mood
    if they last too long.
  45. Cortisol also interacts
    with the immune system in complex ways—
  46. depending on the situation,
  47. it can increase or decrease
    certain immune functions.
  48. In the process of fighting infection,
  49. the immune system
    often creates inflammation.
  50. Cortisol suppresses the immune system’s
    ability to produce inflammation,
  51. which, again,
    can be useful in the short term.
  52. But too much cortisol
    can have negative impacts,
  53. like reducing the immune system’s ability
    to regenerate bone marrow and lymph nodes.
  54. To prevent levels
    from staying high for too long,
  55. cortisol suppresses the signal
    that causes the adrenal glands
  56. to release more cortisol.
  57. Medicinal corticosteroids channel
    cortisol’s effects on the immune system

  58. to fight allergic reactions,
    rashes, and asthma.
  59. All these things are forms
    of inflammation.
  60. There are many synthetic steroids
    that share the same basic mechanism:
  61. they enhance the body’s cortisol supply,
  62. which in turn shuts down
    the hyperactive immune responses
  63. that cause inflammation.
  64. These corticosteroids sneak into cells
    and can turn off the “fire alarm”
  65. by suppressing gene expression
    of inflammatory signals.
  66. The steroids in inhalers and creams impact
    only the affected organ—

  67. the skin, or the lungs.
  68. Intravenous or oral versions, used
    to treat chronic autoimmune conditions
  69. like lupus or inflammatory bowel disease,
    impact the whole body.
  70. With these conditions, the body’s
    immune system attacks its own cells,
  71. a process analogous to a constant
    asthma attack or rash.
  72. A constant low dose of steroids
  73. can help keep this renegade
    immune response under control—
  74. but because of the negative psychological
    and physiological effects
  75. of longterm exposure,
  76. higher doses are reserved
    for emergencies and flare-ups.
  77. While an asthma attack, poison ivy welts,
    and irritable bowel syndrome

  78. might seem totally unrelated,
    they all have something in common:
  79. an immune response
    that’s doing more harm than good.
  80. And while corticosteroids
    won’t give you giant muscles,
  81. they can be the body’s best defense
    against itself.