Fig. 1: Blunting of hypoxia-induced lactatemia by arterial chemoreceptors.
From: Lactate sensing mechanisms in arterial chemoreceptor cells
a, b Top. Scheme of the experimental protocol followed to measure blood lactate (lactate sampling indicated by horizontal brown bars) under normoxic conditions (21% O2) and during exposure to hypoxia (10% or 15% O2 tension, pale blue) or hypercapnia (5% CO2, pale red). Bottom. Plethysmographic recordings showing the average increase in respiratory frequency (breaths/min) during exposure to hypoxia (blue dots; n = 35 mice) or hypercapnia (red dots; n = 27 mice). c Scatter plots of blood lactate levels measured in the various experimental conditions. Values (mean ± SEM) are: normoxia (2.5 ± 0.1 mM, n = 29 mice; gray), hypoxia 15% O2 (3.6 ± 0.3 mM, n = 17 mice; blue), hypoxia 10% O2 (5.8 ± 0.5 mM, n = 23 mice; blue), recovery in normoxia (r21% O2 measured 5 min after returning to normoxia; 4.4 ± 0.3 mM, n = 14 mice; gray), and hypercapnia (2.2 ± 0.5 mM, n = 4 mice; pale red). P-values calculated by one-way ANOVA followed by Tukey’s multiple comparisons post hoc test are indicated. d Scatter plots of blood lactate levels, during normoxia (gray) and hypoxia (blue), in control and mice with carotid body dysfunction due to embryonic or conditional adult deficiency of Hif2α. P-values calculated by one-way ANOVA followed by Tukey’s multiple comparisons post hoc test are indicated. Mean ± SEM values are: TH-HIF2α (normoxia = 3.2 ± 0.6 mM; hypoxia 10% O2 = 8.3 ± 1.2 mM, n = 5 mice); ERT2-HIF2α (normoxia 2.9 ± 0.4 mM; hypoxia 10% O2 = 12.3 ± 1.7 mM, n = 4 mice). Source data are provided as a Source data file.
