By day 12, systolic blood pressure (SBP) increases significantly in Angiotensin II 5-valine infused rats (197±7 mm Hg).The development of hypertension in ANG II infused rats is prevented by losartan treatment. Blood and kidney samples are harvested, subjected to HPLC to separate Angiotensin II 5-valine (exogenous) from Ile5-ANG II (endogenous) and the fractions are measured by radioimmunoassay. In the Angiotensin II 5-valine infused rats treated with losartan, total plasma ANG II levels are elevated to a greater extent than in rats not treated with losartan (289±20 v 119±14 fmol/mL). However, losartan markedly decrease by 88% the enhancement of intrarenal Val5-ANG II content that occurred in the rats infused with Val5-ANG II alone[1].
