AGT and Hypertension: Furthermore, recent hypertension studies show low levels of vitamin D associated with the exaltation of the renin-angiotensin-aldosterone system (RAAS) [6–8]; and, in that respect, our laboratory has demonstrated, in the primary culture of proximal tubular cells of SHRs, that heat shock protein 70 (Hsp70) protects against hypertension induced by angiotensin II by exerting a cytoprotective effect [9].