Using a transgenic renin-dependent model of severe HT and cardiovascular and renal damage created with insertion of the mouse renin gene into the rat genome, the TG(mRen2)27 rat, we found that a blockade of the Ang II type 1 (AT1) receptor with irbesartan prevented TIF, thus supporting a fibrogenic role of Ang II [8]. This evidence concerns the gene REN and hematocrit.