Fig. 2.
Chronic prenatal hypoxia enhances neonatal bradykinin-induced pulmonary arterial relaxation but suppresses postnatal vascular relaxation. A–D: dose-response curves of pulmonary arterial rings exposed to 10 pM–1 μM bradykinin (BK) in an additive manner normalized to maximum 10 μM phenylephrine (PE)-precontracted tension (%T10 μM PE) for fetal and newborn sheep exposed to normoxia and prenatal chronic hypoxia (A and B) and their respective potency (C) and maximum response values (D). Lines show resultant fits with a Hill equation to the dose-response relationships. Values are means ± SE. Data were analyzed by 2-way analysis of variance with a Bonferroni posttest analysis for each dose: *P < 0.05, **P < 0.01, ***P < 0.001, normoxia vs. hypoxia; ††P < 0.01, †††P < 0.001, fetal vs. newborn.