In the SuHx rat model, re-exposure to normoxia led to a partial decrease in right ventricular systolic pressure (from 106±7 to 72±8 mmHg) with persisting hypertension and progressive intima obstruction.
Does SU5416 combined with hypoxia induce persistent pulmonary hypertension and vascular remodeling in rats compared to hypoxia alone?
The SuHx rat model demonstrates partially reversible pulmonary hypertension with persistent progressive intima obstruction upon return to normoxia, providing a detailed haemodynamic characterization of this model.
The SU5416 combined with hypoxia (SuHx) rat model features angio-obliterative pulmonary hypertension resembling human pulmonary arterial hypertension. Despite increasing use of this model, a comprehensive haemodynamic characterisation in conscious rats has not been reported. We used telemetry to characterise haemodynamic responses in SuHx rats and associated these with serial histology. Right ventricular systolic pressure (RVSP) increased to a mean±sd of 106±7 mmHg in response to SuHx and decreased but remained elevated at 72±8 mmHg upon return to normoxia. Hypoxia-only exposed rats showed a similar initial increase in RVSP, a lower maximum RVSP and near-normalisation of RVSP during subsequent normoxia. Progressive vascular remodelling consisted of a four-fold increase in intima thickness, while only minimal changes in media thickness were found. The circadian range in RVSP provided an accurate longitudinal estimate of vascular remodelling. In conclusion, in SuHx rats, re-exposure to normoxia leads to a partial decrease in pulmonary artery pressure, with persisting hypertension and pulmonary vascular remodelling characterised by progressive intima obstruction.
Raaf et al. (Fri,) conducted a other in Pulmonary hypertension. SU5416 combined with hypoxia (SuHx) vs. Hypoxia-only was evaluated on Right ventricular systolic pressure (RVSP). In the SuHx rat model, re-exposure to normoxia led to a partial decrease in right ventricular systolic pressure (from 106±7 to 72±8 mmHg) with persisting hypertension and progressive intima obstruction.