FIGURE 7.
Analysis of Hif-p4h-2gt/gt hearts in an ex vivo ischemia-reperfusion model. A, hearts from 2–5-month-old female Hif-p4h-2gt/gt (gt/gt) mice and age- and gender-matched controls (wt) were isolated and subjected to Langendorff perfusion as indicated. B, preischemic heart rate (HR), LVDP, and coronary flow rate (CFR) were measured after a minimum 30-min stabilization period. C, post-ischemic heart rates during 0–15, 15–30, and 30–45 min of reperfusion. D–F, global ischemia (black horizontal bar) was induced after the stabilization perfusion (the last 10 min of which is shown) by cessation of perfusion for 20 min. Ischemia was followed by 45 min of reperfusion. The values are the means, and the hatched area depicts ± S.E. Coronary flow rate and left ventricle pressure were continuously recorded, and HR, LVDP, and RPP were calculated. The post-ischemic RPP (D), dP/dtmax (E), and coronary flow rate (F) values were calculated relative to the preischemic mean (mean of RPP, dP/dtmax, and coronary flow rate for the last 3 min of stabilization) in the wild-type (n = 7) and Hif-p4h-2gt/gt (n = 9) hearts. The AUC during the 45-min post-ischemic period was calculated using the method of summary measures. *, p < 0.05; **, p < 0.01. G, lactate dehydrogenase (LDH) levels in the venous effluents collected during the reperfusion were determined, and the cumulative lactate dehydrogenase washout for the first 15 min of reperfusion was calculated (units/g of wet weight) for the wild-type (n = 8) and Hif-p4h-2gt/gt (n = 8) hearts. The error bars indicate S.E.