TY - JOUR
T1 - The role of endothelin converting enzyme inhibition during group B Streptococcus-induced pulmonary hypertension in newborn piglets
AU - Navarrete, Cristina T.
AU - Devia, Carlos
AU - Lessa, Andrea C.
AU - Hehre, Dorothy
AU - Young, Karen
AU - Martinez, Octavio
AU - Bancalari, Eduardo
AU - Suguihara, Cleide
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2003/9/1
Y1 - 2003/9/1
N2 - An endothelin-converting enzyme mediates the conversion from low-potency pro-endothelin to potent endothelin-1 (ET-1). Increased ET-1 levels have been observed in pulmonary hypertension of various etiologies in infants. We hypothesized that increased ET-1 levels induce pulmonary hypertension during group B Streptococcus (GBS) infusion, and this can be attenuated by the administration of an endothelin-converting enzyme inhibitor (ECEI). Twenty-two unanesthetized, chronically instrumented newborn piglets received a continuous infusion of GBS (3.5 × 108 colony-forming units/kg/min) while exposed to 100% O2. They were randomly assigned to receive a placebo (PL) or an ECEI (phosphoramidon, 30 mg/kg i.v.) 15 min after sustained pulmonary hypertension. Comparison of hemodynamic measurements and arterial blood gases at baseline and over the first 210 min from the onset of pulmonary hypertension was performed between groups. GBS infusion caused significant increases in mean pulmonary artery pressure, pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), and PVR/SVR, and significant decreases in cardiac output, pH, and base excess. After the administration of ECEI, a significant reduction in pulmonary artery pressure (p < 0.0001), PVR (p < 0.001), and PVR/SVR (p < 0.01) and an improvement in cardiac output (p < 0.01) were observed during GBS infusion. The decrease in pH (p < 0.001) and base excess (p < 0.001) during GBS infusion was less marked after the administration of ECEI compared with the PL. Plasma ET-1 levels were obtained in 20 additional piglets; levels were significantly lower in the ECEI compared with PL after 3 h of GBS infusion (p < 0.02). All animals in the ECEI group survived the study period as opposed to 25% survival in the PL group (p < 0.001). These data suggest that the increased circulating ET-1 levels mediate, in part, the GBS-induced pulmonary hypertension.
AB - An endothelin-converting enzyme mediates the conversion from low-potency pro-endothelin to potent endothelin-1 (ET-1). Increased ET-1 levels have been observed in pulmonary hypertension of various etiologies in infants. We hypothesized that increased ET-1 levels induce pulmonary hypertension during group B Streptococcus (GBS) infusion, and this can be attenuated by the administration of an endothelin-converting enzyme inhibitor (ECEI). Twenty-two unanesthetized, chronically instrumented newborn piglets received a continuous infusion of GBS (3.5 × 108 colony-forming units/kg/min) while exposed to 100% O2. They were randomly assigned to receive a placebo (PL) or an ECEI (phosphoramidon, 30 mg/kg i.v.) 15 min after sustained pulmonary hypertension. Comparison of hemodynamic measurements and arterial blood gases at baseline and over the first 210 min from the onset of pulmonary hypertension was performed between groups. GBS infusion caused significant increases in mean pulmonary artery pressure, pulmonary vascular resistance (PVR), systemic vascular resistance (SVR), and PVR/SVR, and significant decreases in cardiac output, pH, and base excess. After the administration of ECEI, a significant reduction in pulmonary artery pressure (p < 0.0001), PVR (p < 0.001), and PVR/SVR (p < 0.01) and an improvement in cardiac output (p < 0.01) were observed during GBS infusion. The decrease in pH (p < 0.001) and base excess (p < 0.001) during GBS infusion was less marked after the administration of ECEI compared with the PL. Plasma ET-1 levels were obtained in 20 additional piglets; levels were significantly lower in the ECEI compared with PL after 3 h of GBS infusion (p < 0.02). All animals in the ECEI group survived the study period as opposed to 25% survival in the PL group (p < 0.001). These data suggest that the increased circulating ET-1 levels mediate, in part, the GBS-induced pulmonary hypertension.
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U2 - 10.1203/01.PDR.0000078272.77816.1E
DO - 10.1203/01.PDR.0000078272.77816.1E
M3 - Article
C2 - 12788984
AN - SCOPUS:0041968432
VL - 54
SP - 387
EP - 392
JO - Pediatric Research
JF - Pediatric Research
SN - 0031-3998
IS - 3
ER -