Fig. 5.

Cyclosporine A reverses PAH. (A) Three weeks after MCT injection, rats were treated with CSA (1 mg/kg per os) for 2 weeks. CSA decreased mean PA pressure, total pulmonary vascular resistance, and right ventricular hypertrophy; increased cardiac output; and improved vascular remodeling (% medial thickness) (n = 5–6 per group). (B) Both immunohistochemistry and immunoblots (resistance PAs from four rats pooled per lane) show that CSA decreases NFATc2 activation and expression and restores Kv1.5 expression, mimicking VIVIT. PASMCs with activated NFATc2 are shown by arrows in the merged/zoom panels. CSA increases activated caspase 9 and decreases the bcl-2/bax ratio (a representative immunoblot from pooled PAs and densitometry data from three experiments are shown). ∗, P < 0.05 vs. MCT-PAH.