The component of PI3 Kinase P85, Akt, and eNOS were all phosphorylated in IH-rats, and these phosphorylation levels were lower as a result of chronic inhibition of β2AR, meaning that IH-derived activation of β2AR/P85/Akt/eNOS pathway prevents PAH progression. This evidence concerns the gene AKT1 and pulmonary arterial hypertension.