Ang II Accumulation in Rat Renal Endosomes During Ang II-Induced Hypertension

Abstract
Hypertension induced by long-term infusion of angiotensin II (Ang II) is associated with augmented intrarenal Ang II levels to a greater extent than can be explained on the basis of the circulating Ang II levels. Although part of this augmentation is due to AT1 receptor–dependent internalization, the intracellular compartments involved in this Ang II accumulation remain unknown. In the present study, we sought to determine whether Ang II trafficking into renal cortical endosomes is increased during Ang II hypertension, and if so, whether the AT1 receptor antagonist, candesartan, prevents this accumulation. Compared with controls (n=12; 114±2 mm Hg), Ang II-infused rats (n=12; 80 ng/kg/min, SC, for 13 days) developed hypertension with systolic blood pressure rising to 185±4 mm Hg by Day 12. In Ang II hypertensive rats, plasma renin activity was suppressed, whereas plasma and kidney Ang II levels were increased by 3-fold (348±58 versus 119±16 fmol/mL) and 2-fold (399±39 versus 186±26 fmol/g). Intracellular ...