PAH and Sepsis: Due to the downregulation of phenylalanine hydroxylase and tyrosine hydroxylase activities during sepsis, the conversion of phenylalanine and tyrosine to dopamine is blocked, and more phenylalanine and tyrosine may be converted to pseudo-neurotransmitters in the brain, affecting nerve signaling (Gelenberg et al., 1982; Brummelte et al., 2017).