Since it has been demonstrated that AT2R play a physiological role in the hypertrophy of cardiac myocytes under hyperthyroidism conditions [8] and because AT2R is directly associated with the production of the vasodilatory cascade composed by bradykinin, nitric oxide and guanosine cyclic 3′,5′-monophosphate (cGMP) that mediates vasodilatation [18], [29] we evaluated the AngI/AngII and AT2R levels in aortas from hyperthyroid animals. Here, AGT is linked to hyperthyroidism.