Surprise
Physical stressors, psychological stressors, all appear to cause an early stage of immune activation. Even more surprisingly, those immunosuppressive villains, Glucocorticoids, appear to play a major role in this (along with the Sympathetic Nervous System (SNS)). (Location 2532)
==By the one-hour mark, more sustained glucocorticoid and sympathetic activation begins to have the opposite effect, namely, suppressing immunity.== If the stressor ends around then, what have you accomplished with that immunosuppression? Bringing immune function back to where it started, back to baseline (phase B). It is only with major stressors of longer duration, or with really major exposure to glucocorticoids, that the immune system does not just return to baseline, but plummets into a range that really does qualify as immunosuppressing (phase C). For most things that you can measure in the immune system, sustained major stressors drive the numbers down to 40 to 70 percent below baseline. (Location 2535)
⇒ Immune System
⇒ Why is Immunity Suppressed During Stress
⇒ Stress
And that’s what can happen with immune systems that are chronically activated—they begin to mistake part of you for being something invasive, and you’ve got yourself an autoimmune disease. (Location 2559)
During that period of low glucocorticoid levels, people are more likely than normal to flare up with some autoimmune or inflammatory disease—there’s not enough glucocorticoids around to pull off phase B when something stressful occurs. (Location 2566)
a big thing that the Stress-Response does is make sure that immune activation doesn’t spiral into autoimmunity. (Location 2574)
Give someone massive amounts of glucocorticoids, or a huge stressor that has gone on for many hours, and the hormones will be killing lymphocytes indiscriminately, just mowing them down. Have a subtle rise in glucocorticoid levels for a short time (like what is going on at the start of phase B), and the hormones kill only a particular subset of lymphocytes—older ones, ones that don’t work as well. Glucocorticoids, at that stage, are helping to sculpt the immune response, getting rid of lymphocytes that aren’t ideal for the immediate emergency. So that indirectly counts as a version of immune enhancement. (Location 2577)
glucocorticoids and epinephrine are diverting many of those lymphocytes to the specific site of infection, such as the skin. The immune cells aren’t being deactivated—they’re being transferred to the front lines. And a consequence of this is that wounds heal faster. Thus, early on during exposure to a stressor, glucocorticoids and other stress-responsive hormones transiently activate the immune system, enhancing immune defenses, sharpening them, redistributing immune cells to the scenes of infectious battle. Because of the dangers of the systems overshooting into autoimmunity, more prolonged glucocorticoid exposure begins to reverse these effects, bringing the system back to baseline. (Location 2586)
the most time-honored ==treatment== for such diseases is to put people “on steroids”—to give them massive amounts of glucocorticoids. The logic here is obvious: ==by dramatically suppressing the immune system it can no longer attack your pancreas or nervous system==, or whatever is the inappropriate target of its misplaced zeal (and, as an obvious side effect to this approach, your immune system will also not be very effective at defending you against real pathogens). (Location 2594)
see also
Tags: neurobiology science
Superlink: 051 ☣Neurobiology 050 🧠Neuroscience
Source
8 Immunity Stress and Diseases
Created: 16-09-22 16:09