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. Author manuscript; available in PMC: 2013 Nov 1.
Published in final edited form as: Pediatr Res. 2013 Jan 31;73(5):621–629. doi: 10.1038/pr.2013.20

Figure 7.

Figure 7

Contraction (A&B) and relaxation (C&D) responses of pulmonary artery rings from ventilated normal (open circle), PPHN (open triangle) and PPHN+betamethasone (filled square) lamb lungs. Data are mean±SEM for 12 rings for normal lambs and 24 rings for PPHN groups with or without betamethasone. For potassium chloride (KCl) and norepinephrine (NE) contraction responses, basal tone of each ring was normalized to 100%. For relaxation responses in C & D, tone achieved after norepinephrine (norepi) constriction was normalized to 100% for each ring. For panels A & B, *P<0.05 from basal tone; †P<0.05, from PPHN group without betamethasone; §P<0.05, from betamethasone treated group. Betamethasone enhanced the contractile response of rings to KCl and norepinephrine, whereas, rings from normal lambs achieved greater tone at maximal dose of KCl compared to both PPHN groups. For panels C&D, *P<0.05, from NE; †P<0.05, from preceding dose of ATP or S-nitroso-n-acetylpenicillamine (SNAP). Conc. = concentration. ATP and SNAP induced comparable relaxation response in all 3 groups.