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Hemodynamic effects of heat-killed group B beta-hemolytic streptococcus in newborn lambs: role of leukotriene D4.
Pediatr Res. 1992 Feb; 31(2):121-6.PR

Abstract

Group B beta-hemolytic streptococcus (GBS) infection is an important cause of neonatal pneumonia and sepsis. GBS infection is frequently associated with persistent pulmonary hypertension of the newborn. To better understand the early pulmonary hypertension phase of GBS-induced acute lung injury in a conscious animal, we characterized the pulmonary and systemic hemodynamic response of spontaneously breathing, chronically instrumented newborn lambs to injections of heat-killed type Ib GBS, 0.1-9.0 x 10(9) colony forming units. Heat-killed GBS caused marked dose-dependent increases in mean pulmonary arterial pressure and calculated pulmonary vascular resistance, 190 and 370% at the maximum dose, respectively. Similarly, GBS caused dose-dependent increases in mean systemic arterial pressure and systemic vascular resistance (28.5 and 108% at the maximum dose, respectively) and a decrease in cardiac output (33.5%). Arterial oxygen tension worsened at the higher doses. GBS-induced pulmonary hypertension was decreased by two structurally unrelated, putative leukotriene D4 receptor antagonists. Pretreatment with LY171883 blocked GBS-induced pulmonary hypertension by 95%, and WY48,252 attenuated this effect by 27%. Both drugs completely blocked the hemodynamic effects of exogenous leukotriene D4. For comparison, several lambs received bolus injections of live GBS, either alone or after pretreatment with LY171883. The hemodynamic response to live GBS and attenuation of that response by LY171883 were similar to those caused by similar doses of heat-killed GBS. Thus, bolus injections of heat-killed GBS provide a reproducible model of pulmonary hypertension in conscious newborn lambs. In addition, the sulfidopeptide leukotrienes appear to be important mediators of GBS-induced pulmonary hypertension in newborn lambs.

Authors+Show Affiliations

Department of Pediatrics, University of Chicago, Illinois.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

1311829

Citation

Schreiber, M D., et al. "Hemodynamic Effects of Heat-killed Group B Beta-hemolytic Streptococcus in Newborn Lambs: Role of Leukotriene D4." Pediatric Research, vol. 31, no. 2, 1992, pp. 121-6.
Schreiber MD, Covert RF, Torgerson LJ. Hemodynamic effects of heat-killed group B beta-hemolytic streptococcus in newborn lambs: role of leukotriene D4. Pediatr Res. 1992;31(2):121-6.
Schreiber, M. D., Covert, R. F., & Torgerson, L. J. (1992). Hemodynamic effects of heat-killed group B beta-hemolytic streptococcus in newborn lambs: role of leukotriene D4. Pediatric Research, 31(2), 121-6.
Schreiber MD, Covert RF, Torgerson LJ. Hemodynamic Effects of Heat-killed Group B Beta-hemolytic Streptococcus in Newborn Lambs: Role of Leukotriene D4. Pediatr Res. 1992;31(2):121-6. PubMed PMID: 1311829.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Hemodynamic effects of heat-killed group B beta-hemolytic streptococcus in newborn lambs: role of leukotriene D4. AU - Schreiber,M D, AU - Covert,R F, AU - Torgerson,L J, PY - 1992/2/1/pubmed PY - 1992/2/1/medline PY - 1992/2/1/entrez SP - 121 EP - 6 JF - Pediatric research JO - Pediatr Res VL - 31 IS - 2 N2 - Group B beta-hemolytic streptococcus (GBS) infection is an important cause of neonatal pneumonia and sepsis. GBS infection is frequently associated with persistent pulmonary hypertension of the newborn. To better understand the early pulmonary hypertension phase of GBS-induced acute lung injury in a conscious animal, we characterized the pulmonary and systemic hemodynamic response of spontaneously breathing, chronically instrumented newborn lambs to injections of heat-killed type Ib GBS, 0.1-9.0 x 10(9) colony forming units. Heat-killed GBS caused marked dose-dependent increases in mean pulmonary arterial pressure and calculated pulmonary vascular resistance, 190 and 370% at the maximum dose, respectively. Similarly, GBS caused dose-dependent increases in mean systemic arterial pressure and systemic vascular resistance (28.5 and 108% at the maximum dose, respectively) and a decrease in cardiac output (33.5%). Arterial oxygen tension worsened at the higher doses. GBS-induced pulmonary hypertension was decreased by two structurally unrelated, putative leukotriene D4 receptor antagonists. Pretreatment with LY171883 blocked GBS-induced pulmonary hypertension by 95%, and WY48,252 attenuated this effect by 27%. Both drugs completely blocked the hemodynamic effects of exogenous leukotriene D4. For comparison, several lambs received bolus injections of live GBS, either alone or after pretreatment with LY171883. The hemodynamic response to live GBS and attenuation of that response by LY171883 were similar to those caused by similar doses of heat-killed GBS. Thus, bolus injections of heat-killed GBS provide a reproducible model of pulmonary hypertension in conscious newborn lambs. In addition, the sulfidopeptide leukotrienes appear to be important mediators of GBS-induced pulmonary hypertension in newborn lambs. SN - 0031-3998 UR - https://www.unboundmedicine.com/medline/citation/1311829/Hemodynamic_effects_of_heat_killed_group_B_beta_hemolytic_streptococcus_in_newborn_lambs:_role_of_leukotriene_D4_ L2 - https://doi.org/10.1203/00006450-199202000-00006 DB - PRIME DP - Unbound Medicine ER -