When encountering a highly stressful situation – for example, being chased by a bear in the woods – epinephrine is released by the adrenals to support the “fight or flight” response. Epinephrine is integral to the stress response, but epinephrine also has an important place in immune responses as well. Have you ever wondered why epinephrine autoinjectors are used to manage anaphylactic shock in severe allergies?
Anaphylactic shock is usually characterized by systemic vasodilation that causes very low blood pressure. Epinephrine autoinjectors help avoid or treat anaphylactic shock by constricting blood vessels. In addition to being a vascular constrictor, epinephrine is immunomodulatory and suppresses the pro-inflammatory cytokine immune response.
A study by Oberbeck and colleagues in 2004 found that epinephrine, also known as adrenaline, binds to β-adrenergic receptors on immune cells. By doing so, epinephrine signals to decrease circulating monocytes, B cells, T cells, and natural killer cells while also inhibiting pro-inflammatory cytokines such as IL-1, IL-6, and TNF-α. Optimal levels of epinephrine are very important, as extreme elevations can lead to significant immunosuppression, while levels that are depleted could contribute to runaway inflammation.
Epinephrine’s modulatory role in inflammation is an integral part of the body controlling the immune system response. Balance is especially important, as either too high or too low levels can be problematic. Urinary neurotransmitter testing can help determine if epinephrine are at appropriate levels to optimally modulate immune function.