Mast cells are hypersensitive immune cells that release histamine and other inflammatory mediatorsoften in response to oxidative stress, environmental toxins, and immune imbalance. Many patients with MCAS have low levels of glutathione. Role of glutathione in oxidative stress. During oxidative stress there Download Scientific Diagram Did you know one single mast cell can release chemicals that affect your skin, gut, heart, brain, and immune system all at once? That's why MCAS can feel so overwhelming, the Mast Cell Activation Syndrome and Its Impact on the Lymphatics