HMOX1 and hypertensive disorder: In a recent study that used the deoxycorticosterone acetate (DOCA)-salt model of hypertension in Heine oxygenase (HO)-1-/- and HO-1+/+ mice, systolic arterial pressure was significantly elevated in HO-1-/- mice treated with DOCA salt but not in HO-1+/+ mice; in addition, DOCA-salt impaired vasorelaxation was noted in wild-type rats but not in hyperbilirubinemic rats [6].