Fig. 7: Potentiation of the hypoxic response of glomus cells by lactate.
From: Lactate sensing mechanisms in arterial chemoreceptor cells
a Representative amperometric recording of a glomus cell responding to hypoxia (pale blue) and lactate (gray). b, c Box plot representing the distribution of the secretion rates in response to each stimuli (b) and percentage of cells that responded to hypoxia and lactate (c). Mean ± SEM values are: hypoxia: 2839 ± 553 fC/min, n = 18; 5–10 mM lactate: 938 ± 546 fC/min, n = 14; (13 mice). P values calculated by two tails, unpaired t test are indicated. d NADH signal recorded in wild type glomus cells exposed to lactate (10 mM, gray), hypoxia (O2 tension ≈15 mm Hg, pale blue) or both. e Bar diagram and scatter plot of changes in NADH (ΔNADH) in response to hypoxia (pale blue) and hypoxia plus lactate (gray) (n = 6 experiments from 5 mice). P value calculated by two tails, unpaired t test is indicated. f, g Secretory response monitored by amperometry in wild type glomus cells exposed to hypoxia (O2 tension ≈15 mm Hg, pale blue) or lactate (10 mM, gray) plus hypoxia. Values of secretion rates (pC/min) in hypoxia and hypoxia plus lactate are represented by the box plots (n = 20 cells from 14 mice). Mean ± SEM values are: Hypoxia (blue) = 2460 ± 512 fC/min; hypoxia + lactate (gray) = 4172 ± 672 fC/min. P value calculated by two tails, paired t test is indicated. The boxplots in (b, g) indicate median (middle line), 25th, 75th percentile (box), and largest and smallest values extending no further than 1.5 × interquartile range (whiskers). Data beyond the end of the whiskers (outliers) are plotted individually (gray). Source data are provided as a Source data file. h Scheme illustrating potentiation of the CB hypoxic response by lactate and role of CB in lactate homeostasis. + (activation), − (inhibition). Arbitrary units (arb. units).
