REN and Hypertension: In addition to the peripheral RAS, a separate renin-angiotensin system within the CNS has been reported to contribute to the hypertension of animal models including SHR, phenol renal injury hypertension model, and cold-induced hypertension (Huang and Leenen, 1996; Ito et al., 2002; Sun et al., 2002; Ye et al., 2002).