TRH and Wilson disease: Significant, 25- to 37-fold, increases in Tyr-TRH and 93–94% decreases in Val-TRH levels in medulla oblongata (all treatment groups, Table 2) and increases in TRH (13-fold, WD group) and Val-TRH (fivefold, WD group) and 99% decreases in Tyr-TRH concentrations in ventral prostate and a 36-fold increase in liver Tyr-TRH (WD group) (Table 3) were observed following rifaximin administration.