NPR1 and metabolic syndrome: Figure 7 shows that ANP and ANPr were present in greater quantities in mitochondria and fibers from ventricles from MetS-Sh rats than in hearts from Ct-Sh rats. Myocardial I/R injury in MetS rats was associated with intense immunoreactivity that was concentrated on the fibers and mitochondria. The MetS group treated with clofibrate showed a decrease in the expression of ANP and ANPr (Figure 7A,B).