Tissue collection
EXSANGUINATION
At the conclusion of the experiments, rats were killed by exsanguination under isoflurane anesthesia and the heart and lungs rapidly excised. The left ventricle and interventricular septum (IVS) were weighed and transversely sliced at the level of the mid‐wall. The apical portion was minced and snap‐frozen in liquid nitrogen and stored at −80°C and the remainder fixed in 4% paraformaldehyde and routinely processed for immunofluorescence studies. Total lung weight (LW) was measured. Tibia lengths (TL) were also measured in rats and used for the normalization of organ weights, to account for the large differences in body weight between the groups.