Fig. 4.

Ontogeny increases, while LTH reduces, Ca²⁺ spark amplitude. A–F: histograms of Ca²⁺ spark amplitudes for recordings made from fetal, newborn, and adult sheep pulmonary arterial myocytes housed in normoxic or long-term hypoxic conditions. G: bars are for fetal, newborn, and adult normoxic (open) and long-term hypoxic (solid) conditions. ***, ††† P < 0.001 denotes significant difference within (*) groups based on their age using a Kruskal-Wallis 1-way ANOVA on ranks with a Dunn's multiple comparison test and between (†) groups based on their altitude using a Mann-Whitney U-test.