Ventricular performance and glucose uptake in rats during chronic hypobaric hypoxia.

To identify changes of ventricular performance and their relationship to myocardial glucose uptake in Sprague-Dawley rats exposed to hypobaric hypoxia, radionuclide angiocardiograms (n = 34) and 2-[14C]deoxyglucose (2-[14C]DG) autoradiography (n = 14) were performed on rats maintained either for two weeks in air at 380 mmHg (hypoxic group), two weeks in hypobaric hypoxia followed by two weeks of air (recovered group), or in air (control group). Right ventricular ejection fraction (RVEF) was 66% +/- 2% (mean +/- s.e.m.) in controls, 40% +/- 3% during hypoxia, and 60% +/- 2% in recovered rats. LVEF remained unchanged. In controls, RV 2-[14C]DG uptake was 77% +/- 3% of LV uptake. During hypoxia, 2-[14C]DG uptake increased. This increase was greater within the RV than the LV and septum (85 +/- 16% versus 51 +/- 10%, p less than 0.005). The alterations of RV 2-[14C]DG uptake correlated with systolic pulmonary artery pressure (r = 0.77, p = 0.002).