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 Glutathione System from Cyanobacteria to Higher Eukaryotes Encyclopedia MDPI Can L Glutathione Support Energy and Detoxification in Long COVID and ME CFS? RTHM 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.